Co-reporter:Xu Chen, Hong Jiang, Bang Hou, Wei Gong, Yan Liu, and Yong Cui
Journal of the American Chemical Society September 27, 2017 Volume 139(Issue 38) pp:13476-13476
Publication Date(Web):September 5, 2017
DOI:10.1021/jacs.7b06459
A key challenge in heterogeneous catalysis is the design and synthesis of heterogeneous catalysts featuring high catalytic activity, selectivity, and recyclability. Here we demonstrate that high-performance heterogeneous asymmetric catalysts can be engineered from a metal–organic framework (MOF) platform by using a ligand design strategy. Three porous chiral MOFs with the framework formula [Mn2L(H2O)2] are prepared from enantiopure phosphono-carboxylate ligands of 1,1′-biphenol that are functionalized with 3,5-bis(trifluoromethyl)-, bismethyl-, and bisfluoro-phenyl substituents at the 3,3′-position. For the first time, we show that not only chemical stability but also catalytic activity and stereoselectivity of the MOFs can be tuned by modifying the ligand structures. Particularly, the MOF incorporated with −CF3 groups on the pore walls exhibits enhanced tolerance to water, weak acid, and base compared with the MOFs with −F and −Me groups. Under both batch and flow reaction systems, the CF3-containing MOF demonstrated excellent reactivity, selectivity, and recyclability, affording high yields and enantioselectivities for alkylations of indoles and pyrrole with a range of ketoesters or nitroalkenes. In contrast, the corresponding homogeneous catalysts gave low enantioselectivity in catalyzing the tested reactions.
Co-reporter:Xing Han, Qingchun Xia, Jinjing Huang, Yan Liu, Chunxia Tan, and Yong Cui
Journal of the American Chemical Society June 28, 2017 Volume 139(Issue 25) pp:8693-8693
Publication Date(Web):June 8, 2017
DOI:10.1021/jacs.7b04008
Covalent organic frameworks (COFs) featuring chirality, stability, and function are of both fundamental and practical interest, but are yet challenging to achieve. Here we reported the metal-directed synthesis of two chiral COFs (CCOFs) by imine-condensations of enantiopure 1,2-diaminocyclohexane with C3-symmetric trisalicylaldehydes having one or zero 3-tert-butyl group. Powder X-ray diffraction and modeling studies, together with pore size distribution analysis demonstrate that the Zn(salen)-based CCOFs possess a two-dimensional hexagonal grid network with AA stacking. Dramatic enhancement in the chemical stability toward acidic (1 M HCl) and basic (9 M NaOH) conditions was observed for the COF incorporated with tert-butyl groups on the pore walls compared to the nonalkylated analog. The Zn(salen) modules in the CCOFs allow for installing multivariate metals into the frameworks by postsynthetic metal exchange. The exchanged CCOFs maintain high crystallinity and porosity and can serve as efficient and recyclable heterogeneous catalysts for asymmetric cyanation of aldehydes, Diels–Alder reaction, alkene epoxidation, epoxide ring-opening, and related sequential reactions with up to 97% ee.
Co-reporter:Jie Zhang, Xing Han, Xiaowei Wu, Yan Liu, and Yong Cui
Journal of the American Chemical Society June 21, 2017 Volume 139(Issue 24) pp:8277-8277
Publication Date(Web):May 24, 2017
DOI:10.1021/jacs.7b03352
The modular construction of covalent organic frameworks (COFs) provides a convenient platform for designing high-performance functional materials, but the synthetic control over their chirality has been relatively barely studied. Here we report a multivariate strategy to prepare chiral COFs (CCOFs) with controlled crystallinity and stability for asymmetric catalysis. By crystallizing mixtures of triamines with and without chiral organocatalysts and with a dialdehyde, a family of two- and three-component 2D porous CCOFs that adopt two different stacking modes is prepared. The organocatalysts are periodically appended on the channel walls, and their contents, which can be synthetically tuned using a three-component condensation system, greatly affect the chemical stability and crystallinity of CCOFs. Specially, the ternary CCOFs displayed relatively high crystallinity and stability compared with the binary CCOFs. Under harsh conditions, the ternary CCOFs can serve as efficient heterogeneous catalysts for an asymmetric aminooxylation reaction, an aldol reaction, and the Diels–Alder reaction, with the stereoselectivity and diastereoselectivity rivaling or surpassing the homogeneous analogues. This work not only opens up a new synthetic route toward CCOFs, but also provides tunable control of COF crystallintity and stability and, in turn, the properties.
Co-reporter:Qingchun Xia, Zijian Li, Chunxia Tan, Yan Liu, Wei Gong, and Yong Cui
Journal of the American Chemical Society June 21, 2017 Volume 139(Issue 24) pp:8259-8259
Publication Date(Web):May 24, 2017
DOI:10.1021/jacs.7b03113
The search for versatile heterogeneous catalysts with multiple active sites for broad asymmetric transformations has long been of great interest, but it remains a formidable synthetic challenge. Here we demonstrate that multivariate metal–organic frameworks (MTV-MOFs) can be used as an excellent platform to engineer heterogeneous catalysts featuring multiple and cooperative active sites. An isostructural series of 2-fold interpenetrated MTV-MOFs that contain up to three different chiral metallosalen catalysts was constructed and used as efficient and recyclable heterogeneous catalysts for a variety of asymmetric sequential alkene epoxidation/epoxide ring-opening reactions. Interpenetration of the frameworks brings metallosalen units adjacent to each other, allowing cooperative activation, which results in improved efficiency and enantioselectivity over the sum of the individual parts. The fact that manipulation of molecular catalysts in MTV-MOFs can control the activities and selectivities would facilitate the design of novel multifunctional materials for enantioselective processes.
Co-reporter:Jinqiao Dong, Chunxia Tan, Kang Zhang, Yan Liu, Paul J. LowJianwen Jiang, Yong Cui
Journal of the American Chemical Society 2017 Volume 139(Issue 4) pp:1554-1564
Publication Date(Web):January 6, 2017
DOI:10.1021/jacs.6b11422
Chiral NH functionalities-based discrimination is a key feature of Nature’s chemical armory, yet selective binding of biologically active molecules in synthetic systems with high enantioselectivity poses significant challenges. Here we report the assembly of three chiral fluorescent Zn6L6 metallacycles from pyridyl-functionalized Zn(salalen) or Zn(salen) complexes. Each of these metallacycles has a nanoscale hydrophobic cavity decorated with six, three, or zero chiral NH functionalities and packs into a three-dimensional supramolecular porous framework. The binding affinity and enantioselectivity of the metallacycles toward α-hydroxycarboxylic acids, amino acids, small molecule pharamaceuticals (l-dopa, d-penicillamine), and chiral amines increase with the number of chiral NH moieties in the cyclic structure. From single-crystal X-ray diffraction, molecular simulations, and quantum chemical calculations, the chiral recognition and discrimination are attributed to the specific binding of enantiomers in the chiral pockets of the metallacycles. The parent metallacycles are fluorescent with the intensity of emission being linearly related to the enantiomeric composition of the chiral biorelevant guests, which allow them to be utilized in chiral sensing. The fact that manipulation of chiral NH functionalities in metallacycles can control the enantiorecognition of biomolecular complexes would facilitate the design of more effective supramolecular assemblies for enantioselective processes.
Co-reporter:Zijian Li;Yan Liu;Qingchun Xia
Chemical Communications 2017 vol. 53(Issue 91) pp:12313-12316
Publication Date(Web):2017/11/14
DOI:10.1039/C7CC06979K
Two chiral porous MOFs with precise and appropriate spatial arrangements of different metallosalen active sites are synthesized and used as efficient heterogeneous catalysts for asymmetric sequential alkene epoxidation/epoxide ring-opening reactions with enantioselectivity of up to 99%.
Co-reporter:Xiuren Wang, Xing Han, Jie Zhang, Xiaowei Wu, Yan Liu, and Yong Cui
Journal of the American Chemical Society 2016 Volume 138(Issue 38) pp:12332-12335
Publication Date(Web):September 13, 2016
DOI:10.1021/jacs.6b07714
There have been breakthroughs in the development of covalent organic frameworks (COFs) with tunability of composition, structure, and function, but the synthesis of chiral COFs remains a great challenge. Here we report the construction of two-dimensional COFs with chiral functionalities embedded into the frameworks by imine condensations of enantiopure TADDOL-derived tetraaldehydes with 4,4′-diaminodiphenylmethane. Powder X-ray diffraction and computer modeling together with pore size distribution analysis show that one COF has a twofold-interpenetrated grid-type network and the other has a non-interpenetrated grid network. After postsynthetic modification of the chiral dihydroxy groups of TADDOL units with Ti(OiPr)4, the materials are efficient and recyclable heterogeneous catalysts for asymmetric addition of diethylzinc to aldehydes with high enantioselectivity. The results reported here will greatly expand the scope of materials design and engineering for the creation of new types of functional porous materials.
Co-reporter:Chengfeng Zhu, Qingchun Xia, Xu Chen, Yan Liu, Xia Du, and Yong Cui
ACS Catalysis 2016 Volume 6(Issue 11) pp:7590
Publication Date(Web):October 2, 2016
DOI:10.1021/acscatal.6b02359
In this work, we demonstrate cooperative asymmetric catalysis by a metal–organic framework (MOF) as exemplified in the context of catalyzing cyanation of aldehydes with a VO(salen)-MOF, which after oxidation affords remarkably increased stereoselectivity (up to >99% ee) compared to the homogeneous VO(salen) counterpart as a result of the pairs of VO(salen) units in close proximity within its open channels. The cooperative asymmetric catalysis has been evidenced by the significantly decreased stereoselectivity and activity when one VO(salen) in such pairs of VO(salen) units is replaced with one Cu(salen), which results in blocking the VO–VO synergistic pathway while prompting unimolecular activation of substrates. The heterogeneous nature of VO(salen)-MOF has been verified by the fact that it can be easily recycled and reused without significant loss of catalytic activity and enantioselectivity, and its practical utility as asymmetric cyanation catalysist has been illustrated in the gram-scale synthesis of the antiviral natural products (R)- and (S)-enantiomers of tembamide. Our work therefore advances chiral MOF as an attractive platform for cooperative asymmetric catalysis in a variety of syntheses.Keywords: asymmetric catalysis; chiral material; heterogeneoous catalysis; metal−organic framework; porous material
Co-reporter:Yan Liu, Zijian Li, Guozan Yuan, Qingchun Xia, Chen Yuan, and Yong Cui
Inorganic Chemistry 2016 Volume 55(Issue 24) pp:12500-12503
Publication Date(Web):December 6, 2016
DOI:10.1021/acs.inorgchem.6b02151
A homochiral 3D porous metal–organic framework was assembled from a chiral dicarboxylic acid-functionalized Cu(salen)-based catalyst and could serve as an efficient heterogeneous catalyst for aziridination and allylic amination of olefins. Besides easy separation and reuse of the catalyst, the chiral framework confinement could impart substrate size selectivity, enhance catalyst activity, and induce product enantioselectivity.
Co-reporter:Yu Fang, Wei Gong, Lujia Liu, Yan Liu, and Yong Cui
Inorganic Chemistry 2016 Volume 55(Issue 20) pp:10102-10105
Publication Date(Web):September 27, 2016
DOI:10.1021/acs.inorgchem.6b01828
Triple-stranded cluster helicates with heptametallic dicubane cores are synthesized by entrapping metals in the cavities of linear triple helicates based on a C2-symmetrical hexadentate Schiff-base ligand of ortho-substitued biphenol. The helicates are stable in both the solution and solid states, and the copper species could selectively catalyze the oxidation of C–H bonds of alkanes to ketones.
Co-reporter:Jie Zhang, Zijian Li, Wei Gong, Xing Han, Yan Liu, and Yong Cui
Inorganic Chemistry 2016 Volume 55(Issue 15) pp:7229
Publication Date(Web):May 26, 2016
DOI:10.1021/acs.inorgchem.6b00894
Two chiral porous 2,3-dihydroimidazo[1,2-a]pyridine (DHIP)-based metal–organic frameworks (MOFs) are assembled from an enantiopure dipyridyl-functionalized DHIP bridging ligand. The Zn-DHIP MOF shows a good enantioseparation performance toward aromatic sulfoxides, and the heterogeneous adsorbent can be readily recovered and reused without significant degradation of the separation performance.
Co-reporter:Xia Du, Zijian Li, Yan Liu, Shiping Yang and Yong Cui
Dalton Transactions 2015 vol. 44(Issue 29) pp:12999-13002
Publication Date(Web):24 Jun 2015
DOI:10.1039/C5DT01682G
Two chiral porous Ti(salan)-based metal–organic frameworks are constructed and are shown to be efficient and recyclable heterogeneous catalysts for asymmetric cyanation reaction of aldehydes, displaying significantly higher enantioselectivity than their homogeneous counterpart.
Co-reporter:Ke Mo ; Yuhua Yang
Journal of the American Chemical Society 2014 Volume 136(Issue 5) pp:1746-1749
Publication Date(Web):January 21, 2014
DOI:10.1021/ja411887c
A homochiral metal–organic framework (MOF) of an enantiopure 2,2′-dihydroxy-1,1′-biphenyl ligand was constructed. After exchanging one proton of the dihydroxyl group for Li(I) ions, the framework is shown to be a highly efficient and recyclable heterogeneous catalyst for asymmetric cyanation of aldehydes with up to >99% ee. Compared with the homogeneous counterpart, the MOF catalyst exhibits significantly enhanced catalytic activity and enantioselectivity, especially at a low catalyst/substrate ratio, due to that the rigid framework could stabilize the catalytically active monolithium salt of biphenol against its free transformation to catalytically inactive and/or less active assemblies in reactions. The synthetic utility of the cyanation was demonstrated in the synthesis of (S)-bufuralol (a nonselective β-adrenoceptor blocking agent) with 98% ee.
Co-reporter:Jinqiao Dong, Yan Liu and Yong Cui
Chemical Communications 2014 vol. 50(Issue 95) pp:14949-14952
Publication Date(Web):13 Oct 2014
DOI:10.1039/C4CC07648F
Three chiral robust diene-based porous organic frameworks (POFs) are prepared. POF-1 is shown to be an efficient heterogeneous catalyst after metallation for asymmetric conjugation addition with up to 93% ee, and it can also function as a new chiral stationary phase for gas chromatographic separation of racemates.
Co-reporter:Zhiwei Yang, Chengfeng Zhu, Zijian Li, Yan Liu, Guohua Liu and Yong Cui
Chemical Communications 2014 vol. 50(Issue 63) pp:8775-8778
Publication Date(Web):18 Jun 2014
DOI:10.1039/C4CC03308F
Two chiral porous Fe(salen)-based metal–organic frameworks are constructed and are shown to be efficient and recyclable heterogeneous catalysts for asymmetric oxidation of sulfides to sulfoxides with an enantioselectivity of up to 96%.
Co-reporter:Xiaobing Xi, Yan Liu, and Yong Cui
Inorganic Chemistry 2014 Volume 53(Issue 5) pp:2352-2354
Publication Date(Web):February 10, 2014
DOI:10.1021/ic4027865
Homochiral coordination polymers based on zigzag or helical polymers are assembled from a semiflexible fluorescent bipyridyl ligand and linear coordinated AgI ions; they exhibit unusual temperature-dependent photoluminescence behavior, including multistep changes in energy and intensity upon cooling.
Co-reporter:YongWu Peng;ChengFeng Zhu
Science China Chemistry 2014 Volume 57( Issue 1) pp:107-113
Publication Date(Web):2014 January
DOI:10.1007/s11426-013-5012-8
Chiral Schiff-base ligand L was synthesized through six steps in good overall yield from readily available 2-tert-butylphenol and was used to construct one chiral porous metal-metallosalen framework, [Zn5(µ3-OH)2(ZnL)4(H2O)2]·18H2O (1, L = 5′,5″-(1E, 1′E)-(1R, 2R)-cyclohexane-1,2-diylbis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(3′-tert-butyl-4′-hydroxybiphenyl-4-carboxylic acid), under mild reaction conditions. 1 was characterized by IR, TGA, CD, UV, PL, single-crystal and powder X-ray crystallography. The structure of 1 displays a 3-fold interpenetrating 3D framework with 1D channel of 1.14 nm × 0.58 nm and imparts unique Zn(salen) units on the surface of the pore, in which (ZnL)2 dimer acts as multi-functionlized metalloligand. 1 is thermally robust with network decomposition temperature of 400 °C and it also exhibits strong photoluminescence in the visible region.
Co-reporter:Jinqiao Dong;Yanfang Zhou;Fangwei Zhang ; Yong Cui
Chemistry - A European Journal 2014 Volume 20( Issue 21) pp:6455-6461
Publication Date(Web):
DOI:10.1002/chem.201304606
Abstract
A highly fluorescent coordination cage [Zn8L4I8] has been constructed by treating enantiopure pyridyl-functionalized metallosalalen units (L) with zinc(II) iodide and characterized by a variety of techniques including microanalysis, thermogravimetric analysis (TGA), circular dichroism (CD) spectroscopy, and single-crystal and powder X-ray diffraction. Strong intermolecular π–π, CH⋅⋅⋅π, and CH⋅⋅⋅I interactions direct packing of the cage molecules to generate a 3D polycage network interconnected by pentahedral cages formed by adjacent pentamers. The cage has an amphiphilic helical cavity decorated with chiral NH functionalities capable of interactions with guest species such as saccharides. The fluorescence of the cage was greatly enhanced by five enantiomeric saccharides in solution, with enantioselectivity factors of 2.480–4.943, and by five enantiomeric amines in the solid state, with enantioselective fluorescence enhancement ratios of 1.30–3.60. This remarkable chiral sensing of both saccharides and amines with impressive enantioselectivity may result from the steric confinement of the cavity as well as its conformational rigidity. It holds great promise for the development of novel chiral cage materials for sensing applications.
Co-reporter: Yan Liu;Dr. Xiaobing Xi;Chengcheng Ye;Tengfei Gong;Zhiwei Yang; Yong Cui
Angewandte Chemie International Edition 2014 Volume 53( Issue 50) pp:13821-13825
Publication Date(Web):
DOI:10.1002/anie.201408896
Abstract
Two chiral carboxylic acid functionalized micro- and mesoporous metal–organic frameworks (MOFs) are constructed by the stepwise assembly of triple-stranded heptametallic helicates with six carboxylic acid groups. The mesoporous MOF with permanent porosity functions as a host for encapsulation of an enantiopure organic amine catalyst by combining carboxylic acids and chiral amines in situ through acid–base interactions. The organocatalyst-loaded framework is shown to be an efficient and recyclable heterogeneous catalyst for the asymmetric direct aldol reactions with significantly enhanced stereoselectivity in relative to the homogeneous organocatalyst.
Co-reporter:Weimin Xuan, Chengcheng Ye, Mengni Zhang, Zhijie Chen and Yong Cui
Chemical Science 2013 vol. 4(Issue 8) pp:3154-3159
Publication Date(Web):15 May 2013
DOI:10.1039/C3SC50487E
A chiral porous zeolite-like metal-organic framework is constructed by using mixed ligands of dipyridyl-functionalized chiral Ti(salan) and biphenyl-4,4′-dicarboxylate. The framework containing salan-bound Ti4O6 clusters consists of both hydrophobic and amphiphilic mesocages and is shown to be an efficient and recyclable heterogeneous catalyst for the oxidation of thioethers to sulfoxides by aqueous H2O2 (up to 82% ee), displaying markedly enhanced enantioselectivity over the homogeneous catalyst by providing a cavity confinement effect. This work highlights the potential of significantly improving enantioselectivity of homogeneous catalysts by using MOFs as support structures.
Co-reporter:Chengfeng Zhu, Xu Chen, Zhiwei Yang, Xia Du, Yan Liu and Yong Cui
Chemical Communications 2013 vol. 49(Issue 64) pp:7120-7122
Publication Date(Web):08 Jul 2013
DOI:10.1039/C3CC43225D
Chiral porous metal–metallosalan frameworks are constructed from an unsymmetrical chiral pyridinecarboxylate ligand derived from Ti(salan) and are shown to be heterogeneous catalysts for asymmetric oxidation of thioethers to sulfoxides.
Co-reporter:Yongwu Peng, Tengfei Gong and Yong Cui
Chemical Communications 2013 vol. 49(Issue 74) pp:8253-8255
Publication Date(Web):16 Jul 2013
DOI:10.1039/C3CC43549K
A chiral porous metal–organic framework of an axially C2-symmetric 1,1′-biphenol ligand is constructed and can be used as a solid-state host to enanioselectively adsorb mandelates with up to 93.1% ee and to entrap achiral tropolone ethers and induce their asymmetric photocyclization with up to 98.5% ee.
Co-reporter:Yan Liu, Ke Mo, and Yong Cui
Inorganic Chemistry 2013 Volume 52(Issue 18) pp:10286-10291
Publication Date(Web):September 5, 2013
DOI:10.1021/ic400598x
Porous and robust 12-connected metal–organic frameworks (MOFs) were constructed by linking tetranuclear lanthanide (Ln) carbonate clusters with organoboron-derived tricarboxylate bridging ligands. The high-connectivity Ln-MOFs feature remarkable thermal and hydrolytic stability and a large number of isolated Lewis acid B(III) and Ln(III) sites on the pore surfaces. The Nd-MOF assisted with sodium dodecylsulfate was found to be highly effective, recyclable, and reusable heterogeneous catalyst for the carbonyl allylation reaction, the Diels–Alder reaction, and the Strecker-type reaction in water. The transformations were cocatalyzed by Nd(III) and B(III) Lewis acids, with activities much higher than those of the individual organoboron and lanthanide counterparts and their mixture. This work highlights the potential of generating highly efficient water-tolerant solid catalysts via heterogenization of different weak and/or mild Lewis acids in confined spaces of robust MOFs.
Co-reporter:Weimin Xuan, Chengfeng Zhu, Yan Liu and Yong Cui
Chemical Society Reviews 2012 vol. 41(Issue 5) pp:1677-1695
Publication Date(Web):18 Oct 2011
DOI:10.1039/C1CS15196G
Metal–organic frameworks (MOFs) have emerged as a new type of porous materials for diverse applications. Most open MOFs reported to date are microporous (pore sizes <2 nm), and only a small fraction of MOFs with ordered mesoscale domains (2–50 nm) is reported. This tutorial review covers recent advances in the field of mesoporous MOFs (mesoMOFs), including their design and synthesis, porosity activation and surface modification, and potential applications in storage and separation, catalysis, drug delivery and imaging. Their specificities are dependent on the pore shape, size, and chemical environments of the cages or channels. The relationship between the structures and functions is discussed. The future outlook for the field is discussed in the context of current challenges in applications of mesoporous materials.
Co-reporter:Chengfeng Zhu ; Guozan Yuan ; Xu Chen ; Zhiwei Yang
Journal of the American Chemical Society 2012 Volume 134(Issue 19) pp:8058-8061
Publication Date(Web):April 30, 2012
DOI:10.1021/ja302340b
Chiral nanoporous metal–organic frameworks are constructed by using dicarboxyl-functionalized chiral Ni(salen) and Co(salen) ligands. The Co(salen)-based framework is shown to be an efficient and recyclable heterogeneous catalyst for hydrolytic kinetic resolution (HKR) of racemic epoxides with up to 99.5% ee. The MOF structure brings Co(salen) units into a highly dense arrangement and close proximity that enhances bimetallic cooperative interactions, leading to improved catalytic activity and enantioselectivity in HKR compared with its homogeneous analogues, especially at low catalyst/substrate ratios.
Co-reporter:Weimin Xuan ; Mengni Zhang ; Yan Liu ; Zhijie Chen
Journal of the American Chemical Society 2012 Volume 134(Issue 16) pp:6904-6907
Publication Date(Web):April 11, 2012
DOI:10.1021/ja212132r
The self-assembly of enantiopure pyridyl-functionalized metallosalan units affords a homochiral helicate cage, [Zn8L4Cl8], in which the optical rotation of each ligand is increased by a factor of 10 upon coordination. The octanuclear cage featuring a chiral amphiphilic cavity exhibits enantioselective luminescence enhancement by amino acids in solution. The cage exists in two different crystalline polymorphic forms that possess porous structures built of helicate cages interconnected by 1D channels or pentahedral cages and have the ability to separate small racemic molecules by adsorption but with different enantioselectivities.
Co-reporter:Chengfeng Zhu, Weimin Xuan and Yong Cui
Dalton Transactions 2012 vol. 41(Issue 14) pp:3928-3932
Publication Date(Web):25 Oct 2011
DOI:10.1039/C1DT11584G
Two microporous three-dimensional metal–metallosalen frameworks are constructed from a dicarboxyl-functionalized Schiff base ligand and their H2, CO2 and CH4 adsorption capacities and fluorescence quenching behavior to the vapor of nitroaromatic compounds are studied.
Co-reporter:Guozan Yuan, Chengfeng Zhu, Yan Liu and Yong Cui
Chemical Communications 2011 vol. 47(Issue 11) pp:3180-3182
Publication Date(Web):31 Jan 2011
DOI:10.1039/C0CC03981K
A robust 3D Mn-based metal–organic framework containing metallosalen hexamers is synthesized and its nano- and microcrystals are fabricated by using surfactant-mediated hydrothermal and solvent precipitation methods; the particles exhibit an inverse size-dependent effect of magnetic resonance relaxivity behaviors.
Co-reporter:Xiaobing Xi, Taiwei Dong, Gao Li and Yong Cui
Chemical Communications 2011 vol. 47(Issue 13) pp:3831-3833
Publication Date(Web):14 Feb 2011
DOI:10.1039/C0CC05128D
A 1D chiral metallosalen polymer with free pyridine groups is self-assembled and its molecular weight, conformation, architecture and optical property are controlled by depolymerization through sunlight irradiation or alcohol inclusions.
Co-reporter:Xiaobing Xi;Yu Fang;Taiwei Dong ; Yong Cui
Angewandte Chemie 2011 Volume 123( Issue 5) pp:1186-1190
Publication Date(Web):
DOI:10.1002/ange.201004885
Co-reporter:Xiaobing Xi;Yu Fang;Taiwei Dong ; Yong Cui
Angewandte Chemie International Edition 2011 Volume 50( Issue 5) pp:1154-1158
Publication Date(Web):
DOI:10.1002/anie.201004885
Co-reporter:Yan Liu;Xin Xu;WeiMin Xuan;ChengFeng Zhu
Science China Chemistry 2011 Volume 54( Issue 9) pp:
Publication Date(Web):2011 September
DOI:10.1007/s11426-011-4355-2
Rigid trigonal tris(3-pyridylduryl)borane L was synthesized through four steps in good overall yield from readily available 1,2,4,5-tetramethylbenzene and was used to construct two porous cadmium (II) complexes Cd(L)X2·G (X = Cl, Br; G = guset molecules), 1 (Cd(L)Cl2·EtOH·iPrOH·3H2O) and 2 (Cd(L)Br2·MeOH·C7H8·3H2O), under mild reaction conditions. 1 and 2 are isostructural and featured with 3D porous metal-organoboron framewoks with rtl topology, in which L acts as a 3-connected node while a dicadmium motif serves as 6-connected node. In addition, 1 and 2 exhibit strong photoluminescence in the visible region and 1 shows moderate adsorption ability of carbon dioxide at 273 K.
Co-reporter:Yan Liu;Weimin Xuan
Advanced Materials 2010 Volume 22( Issue 37) pp:4112-4135
Publication Date(Web):
DOI:10.1002/adma.201000197
Abstract
Owing to the potential applications in technological areas such as gas storage, catalysis, separation, sensing and nonlinear optics, tremendous efforts have been devoted to the development of porous metal-organic frameworks (MOFs) over the past ten years. Homochiral porous MOFs are particularly attractive candidates as heterogeneous asymmetric catalysts and enantioselective adsorbents and separators for production of optically active organic compounds due to the lack of homochiral inorganic porous materials such as zeolites. In this review, we summarize the recent research progress in homochiral MOF materials, including their synthetic strategy, distinctive structural features and latest advances in asymmetric heterogeneous catalysis and enantioselective separation.
Co-reporter:Guozan Yuan, Chengfeng Zhu, Yan Liu, Yu Fang and Yong Cui
Chemical Communications 2010 vol. 46(Issue 13) pp:2307-2309
Publication Date(Web):23 Jan 2010
DOI:10.1039/B923259A
Chiral crystalline organic microtubules, microspheres and microleaves are controllably assembled from twisted bispyridyl-based biphenyl and tetrameric water clusters and undergo reversible phase transformations and luminescence switching triggered by water clusters removal and uptake.
Co-reporter:Yan Liu, Xin Xu, Qingchun Xia, Guozan Yuan, Qizhuang He and Yong Cui
Chemical Communications 2010 vol. 46(Issue 15) pp:2608-2610
Publication Date(Web):04 Feb 2010
DOI:10.1039/B923365B
Three 3D Ag-based metal–organoboron frameworks with unprecedented multiple topological isomerism of 3-connected networks were assembled and could control the release of silver ions in biocidal concentration in solution giving excellent antibacterial activities and durability against Gram-negative bacteria and Gram-positive human pathogens.
Co-reporter:Gao Li, Xiaobing Xi, Weimin Xuan, Taiwei Dong and Yong Cui
CrystEngComm 2010 vol. 12(Issue 8) pp:2424-2428
Publication Date(Web):18 May 2010
DOI:10.1039/C001121E
Homochiral helical coordination polymers [ML] have been developed via the solvothermal reaction of the chiral di-3-pyridyl-functionalized salen complex (R,R)-(−)-N,N′-bis(3-tert-butyl-5-(3-pyridyl)salicylidene)-1,2-diaminocyclohexane (H2L) with various metal salts MX2 (MX2 = Zn(NO3)2, 1; CoCl2, 2; Ni(NO3)2, 3 and Mn(OAc)2, 4) and characterized by a variety of techniques including microanalysis, IR, thermogravimetric analysis (TGA), circular dichroism (CD) spectroscopy and powder and single-crystal X-ray diffraction. Salen L ligands link adjacent metal centers to form 1D helical chains using tetradentate N2O2 donors and pyridine groups, the pitch lengths of the helices can be tuned by metal cations.
Co-reporter:Taifeng Liu;Yan Liu;Weimin Xuan
Angewandte Chemie International Edition 2010 Volume 49( Issue 24) pp:
Publication Date(Web):
DOI:10.1002/anie.201002350
Co-reporter:Taifeng Liu;Yan Liu;Weimin Xuan
Angewandte Chemie International Edition 2010 Volume 49( Issue 24) pp:4121-4124
Publication Date(Web):
DOI:10.1002/anie.201000416
Co-reporter:Taifeng Liu;Yan Liu;Weimin Xuan
Angewandte Chemie 2010 Volume 122( Issue 24) pp:
Publication Date(Web):
DOI:10.1002/ange.201002350
Co-reporter:Taifeng Liu;Yan Liu;Weimin Xuan
Angewandte Chemie 2010 Volume 122( Issue 24) pp:4215-4218
Publication Date(Web):
DOI:10.1002/ange.201000416
Co-reporter:Guozan Yuan ; Chengfeng Zhu ; Yan Liu ; Weimin Xuan
Journal of the American Chemical Society 2009 Volume 131(Issue 30) pp:10452-10460
Publication Date(Web):July 9, 2009
DOI:10.1021/ja901154p
Three homochiral 3D frameworks are assembled based on periodically ordered arrays of helices built from axial chiral 3,3′-bipyridine-5,5′,6,6′-tetramethyl-2,2′-dimethoxy-1,1′-biphenyl ligands and linearly coordinated Ag(I) ions. The aggregation behavior of silver salts and the ditopic ligand in solutions was investigated by a variety of techniques, including 1H NMR, UV−vis, CD, GPC and MALDI-TOF. The cationic polymer skeleton exhibits an unprecedented conformational polymorphism in the solid-state, folding into two-, three- and four-fold helices with NO3−, PF6− and ClO4− as the counteranion, respectively. The two-fold helices cross-link via argentophilic Ag−Ag interactions to form sextuple helices, which lead to a three-dimensional (3D) chiral framework. The three-fold or four-fold helices, on the other hand, self-associates in pairs to form three-dimensional tubular architectures. This anion-dependent self-assembly behavior can be rationalized by considering the sizes, geometries and binding abilities of the counteranions and subsequent chain conformation to minimize steric repulsions and maximize secondary interactions.
Co-reporter:Gao Li, Chengfeng Zhu, Xiaobing Xi and Yong Cui
Chemical Communications 2009 (Issue 16) pp:2118-2120
Publication Date(Web):23 Mar 2009
DOI:10.1039/B901574D
A dynamic porous coordination network with a hydrophobic channel was assembled from stretchable 1D metallosalen polymer, which has the ability to recognize and, particularly, separate aromatic hydrocarbons from aliphatic mixtures with high selectivity.
Co-reporter:Yan Liu, Weimin Xuan, Hui Zhang and Yong Cui
Inorganic Chemistry 2009 Volume 48(Issue 21) pp:10018-10023
Publication Date(Web):October 1, 2009
DOI:10.1021/ic9002675
Homochiral octupolar metal−organoboron frameworks with the general formula [M2L(OH)(MeOH)]·3H2O [M = Co (1), Mn (2), Ni (3), Cu (4), Zn (5), Cd (6)] have been constructed from racemic C3-symmetric tris(4-benzoic acid)tridurylborane and the divalent metal ions. Compounds 1−6 are isostructural and crystallize in the chiral cubic space group F432, and they adopt an eightfold-interpenetrating (10,3)-a network formed by linking bimetal building blocks with three bidentate carboxylate groups of bridging Λ-L ligands. Bulk crystals of each of the six compounds are not a racemic mixture, and their optical activity and enantiomeric nature were demonstrated by solid-state circular dichroism spectra. Consistent with their polar structures, the colorless compounds 5 and 6 exhibit powder second harmonic generation intensities 3−4 times higher than that of potassium dihydrogen phosphate, making them, to the best of our knowledge, the first two examples of NLO-active, homochiral octupolar metal−organic solids.
Co-reporter:Guozan Yuan;Chengfeng Zhu;Weimin Xuan
Chemistry - A European Journal 2009 Volume 15( Issue 26) pp:6428-6434
Publication Date(Web):
DOI:10.1002/chem.200900037
Co-reporter:Yan Liu;Xin Xu;Fakun Zheng
Angewandte Chemie International Edition 2008 Volume 47( Issue 24) pp:4538-4541
Publication Date(Web):
DOI:10.1002/anie.200800586
Co-reporter:Gao Li;Weibin Yu;Jia Ni;Taifeng Liu;Yan Liu;Enhong Sheng Dr.
Angewandte Chemie International Edition 2008 Volume 47( Issue 7) pp:1245-1249
Publication Date(Web):
DOI:10.1002/anie.200704347
Co-reporter:Yan Liu;Xin Xu;Fakun Zheng
Angewandte Chemie 2008 Volume 120( Issue 24) pp:4614-4617
Publication Date(Web):
DOI:10.1002/ange.200800586
Co-reporter:Gao Li;Weibin Yu;Jia Ni;Taifeng Liu;Yan Liu;Enhong Sheng Dr.
Angewandte Chemie 2008 Volume 120( Issue 7) pp:1265-1269
Publication Date(Web):
DOI:10.1002/ange.200704347
Co-reporter:Yan Liu;Gao Li;Xing Li Dr. Dr.
Angewandte Chemie International Edition 2007 Volume 46(Issue 33) pp:
Publication Date(Web):19 JUL 2007
DOI:10.1002/anie.200701056
A holey host: An octupolar porous metal–organic framework with a Td-symmetric supercage structure (see picture; green: center of the octapolar structure) exhibits a powder second harmonic generation (SHG) intensity about 15 times higher than that of KH2PO4. This anionic open framework is highly thermally stable, displays high ion-exchange capacities with the cations NH4+, Na+, and K+, and, more importantly, exhibits an unprecedented cation-dependent NLO activity.
Co-reporter:Yan Liu;Gao Li;Xing Li Dr. Dr.
Angewandte Chemie 2007 Volume 119(Issue 33) pp:
Publication Date(Web):19 JUL 2007
DOI:10.1002/ange.200701056
Ein löchriger Wirt: Die Oberton(SHG)-Intensität des Pulvers eines octupolaren porösen metall-organischen Gerüsts mit einer Td-symmetrischen Käfigstruktur (siehe Bild; grün: Zentrum der octopolaren Struktur) ist etwa 15-mal höher als diejenige von KH2PO4. Das offene anionische Gerüst ist thermisch sehr stabil, weist eine hohe Ionenaustauschkapazität für NH4+, Na+ und K+ auf und zeigt eine neuartige kationenabhängige NLO-Aktivität.
Co-reporter:Gao Li, Chengfeng Zhu, Xiaobing Xi and Yong Cui
Chemical Communications 2009(Issue 16) pp:NaN2120-2120
Publication Date(Web):2009/03/23
DOI:10.1039/B901574D
A dynamic porous coordination network with a hydrophobic channel was assembled from stretchable 1D metallosalen polymer, which has the ability to recognize and, particularly, separate aromatic hydrocarbons from aliphatic mixtures with high selectivity.
Co-reporter:Yan Liu, Xin Xu, Qingchun Xia, Guozan Yuan, Qizhuang He and Yong Cui
Chemical Communications 2010 - vol. 46(Issue 15) pp:NaN2610-2610
Publication Date(Web):2010/02/04
DOI:10.1039/B923365B
Three 3D Ag-based metal–organoboron frameworks with unprecedented multiple topological isomerism of 3-connected networks were assembled and could control the release of silver ions in biocidal concentration in solution giving excellent antibacterial activities and durability against Gram-negative bacteria and Gram-positive human pathogens.
Co-reporter:Guozan Yuan, Chengfeng Zhu, Yan Liu, Yu Fang and Yong Cui
Chemical Communications 2010 - vol. 46(Issue 13) pp:NaN2309-2309
Publication Date(Web):2010/01/23
DOI:10.1039/B923259A
Chiral crystalline organic microtubules, microspheres and microleaves are controllably assembled from twisted bispyridyl-based biphenyl and tetrameric water clusters and undergo reversible phase transformations and luminescence switching triggered by water clusters removal and uptake.
Co-reporter:Xia Du, Zijian Li, Yan Liu, Shiping Yang and Yong Cui
Dalton Transactions 2015 - vol. 44(Issue 29) pp:NaN13002-13002
Publication Date(Web):2015/06/24
DOI:10.1039/C5DT01682G
Two chiral porous Ti(salan)-based metal–organic frameworks are constructed and are shown to be efficient and recyclable heterogeneous catalysts for asymmetric cyanation reaction of aldehydes, displaying significantly higher enantioselectivity than their homogeneous counterpart.
Co-reporter:Weimin Xuan, Chengfeng Zhu, Yan Liu and Yong Cui
Chemical Society Reviews 2012 - vol. 41(Issue 5) pp:NaN1695-1695
Publication Date(Web):2011/10/18
DOI:10.1039/C1CS15196G
Metal–organic frameworks (MOFs) have emerged as a new type of porous materials for diverse applications. Most open MOFs reported to date are microporous (pore sizes <2 nm), and only a small fraction of MOFs with ordered mesoscale domains (2–50 nm) is reported. This tutorial review covers recent advances in the field of mesoporous MOFs (mesoMOFs), including their design and synthesis, porosity activation and surface modification, and potential applications in storage and separation, catalysis, drug delivery and imaging. Their specificities are dependent on the pore shape, size, and chemical environments of the cages or channels. The relationship between the structures and functions is discussed. The future outlook for the field is discussed in the context of current challenges in applications of mesoporous materials.
Co-reporter:Zhiwei Yang, Chengfeng Zhu, Zijian Li, Yan Liu, Guohua Liu and Yong Cui
Chemical Communications 2014 - vol. 50(Issue 63) pp:NaN8778-8778
Publication Date(Web):2014/06/18
DOI:10.1039/C4CC03308F
Two chiral porous Fe(salen)-based metal–organic frameworks are constructed and are shown to be efficient and recyclable heterogeneous catalysts for asymmetric oxidation of sulfides to sulfoxides with an enantioselectivity of up to 96%.
Co-reporter:Chengfeng Zhu, Weimin Xuan and Yong Cui
Dalton Transactions 2012 - vol. 41(Issue 14) pp:NaN3932-3932
Publication Date(Web):2011/10/25
DOI:10.1039/C1DT11584G
Two microporous three-dimensional metal–metallosalen frameworks are constructed from a dicarboxyl-functionalized Schiff base ligand and their H2, CO2 and CH4 adsorption capacities and fluorescence quenching behavior to the vapor of nitroaromatic compounds are studied.
Co-reporter:Guozan Yuan, Chengfeng Zhu, Yan Liu and Yong Cui
Chemical Communications 2011 - vol. 47(Issue 11) pp:NaN3182-3182
Publication Date(Web):2011/01/31
DOI:10.1039/C0CC03981K
A robust 3D Mn-based metal–organic framework containing metallosalen hexamers is synthesized and its nano- and microcrystals are fabricated by using surfactant-mediated hydrothermal and solvent precipitation methods; the particles exhibit an inverse size-dependent effect of magnetic resonance relaxivity behaviors.
Co-reporter:Yongwu Peng, Tengfei Gong and Yong Cui
Chemical Communications 2013 - vol. 49(Issue 74) pp:NaN8255-8255
Publication Date(Web):2013/07/16
DOI:10.1039/C3CC43549K
A chiral porous metal–organic framework of an axially C2-symmetric 1,1′-biphenol ligand is constructed and can be used as a solid-state host to enanioselectively adsorb mandelates with up to 93.1% ee and to entrap achiral tropolone ethers and induce their asymmetric photocyclization with up to 98.5% ee.
Co-reporter:Xiaobing Xi, Taiwei Dong, Gao Li and Yong Cui
Chemical Communications 2011 - vol. 47(Issue 13) pp:NaN3833-3833
Publication Date(Web):2011/02/14
DOI:10.1039/C0CC05128D
A 1D chiral metallosalen polymer with free pyridine groups is self-assembled and its molecular weight, conformation, architecture and optical property are controlled by depolymerization through sunlight irradiation or alcohol inclusions.
Co-reporter:Weimin Xuan, Chengcheng Ye, Mengni Zhang, Zhijie Chen and Yong Cui
Chemical Science (2010-Present) 2013 - vol. 4(Issue 8) pp:NaN3159-3159
Publication Date(Web):2013/05/15
DOI:10.1039/C3SC50487E
A chiral porous zeolite-like metal-organic framework is constructed by using mixed ligands of dipyridyl-functionalized chiral Ti(salan) and biphenyl-4,4′-dicarboxylate. The framework containing salan-bound Ti4O6 clusters consists of both hydrophobic and amphiphilic mesocages and is shown to be an efficient and recyclable heterogeneous catalyst for the oxidation of thioethers to sulfoxides by aqueous H2O2 (up to 82% ee), displaying markedly enhanced enantioselectivity over the homogeneous catalyst by providing a cavity confinement effect. This work highlights the potential of significantly improving enantioselectivity of homogeneous catalysts by using MOFs as support structures.
Co-reporter:Chengfeng Zhu, Xu Chen, Zhiwei Yang, Xia Du, Yan Liu and Yong Cui
Chemical Communications 2013 - vol. 49(Issue 64) pp:NaN7122-7122
Publication Date(Web):2013/07/08
DOI:10.1039/C3CC43225D
Chiral porous metal–metallosalan frameworks are constructed from an unsymmetrical chiral pyridinecarboxylate ligand derived from Ti(salan) and are shown to be heterogeneous catalysts for asymmetric oxidation of thioethers to sulfoxides.
Co-reporter:Jinqiao Dong, Yan Liu and Yong Cui
Chemical Communications 2014 - vol. 50(Issue 95) pp:NaN14952-14952
Publication Date(Web):2014/10/13
DOI:10.1039/C4CC07648F
Three chiral robust diene-based porous organic frameworks (POFs) are prepared. POF-1 is shown to be an efficient heterogeneous catalyst after metallation for asymmetric conjugation addition with up to 93% ee, and it can also function as a new chiral stationary phase for gas chromatographic separation of racemates.
![Phenol, 2,2'-[(1S,2S)-1,2-cyclohexanediylbis[(E)-nitrilomethylidyne]]bis[4-(1,1-dimethylethyl)-6-[(1E)-2-(4-pyridinyl)ethenyl]-](/data/chemimg/1373349-34-8.png)
![Phenol, 2,2'-[(1S,2S)-1,2-cyclohexanediylbis[(E)-nitrilomethylidyne]]bis[4-(1,1-dimethylethyl)-6-[(1E)-2-(4-pyridinyl)ethenyl]-](/data/chemimg/1373349-34-8_b.png)
![Phenol, 2,2'-[(1R,2R)-1,2-cyclohexanediylbis[(E)-nitrilomethylidyne]]bis[4-(1,1-dimethylethyl)-6-[(1E)-2-(4-pyridinyl)ethenyl]-](/data/chemimg/1373349-33-7.png)
![Phenol, 2,2'-[(1R,2R)-1,2-cyclohexanediylbis[(E)-nitrilomethylidyne]]bis[4-(1,1-dimethylethyl)-6-[(1E)-2-(4-pyridinyl)ethenyl]-](/data/chemimg/1373349-33-7_b.png)
![Pyridine, 4,4'-[(1S)-2,2'-dimethoxy-5,5',6,6'-tetramethyl[1,1'-biphenyl]-3,3'-diyl]bis-](/data/chemimg/1178516-28-3.png)
![Pyridine, 4,4'-[(1S)-2,2'-dimethoxy-5,5',6,6'-tetramethyl[1,1'-biphenyl]-3,3'-diyl]bis-](/data/chemimg/1178516-28-3_b.png)
![5-(1,1-dimethylethyl)-2-hydroxy-3-[(1E)-2-(4-pyridinyl)ethenyl]-Benzaldehyde](/data/chemimg/1373284-30-0.png)
![5-(1,1-dimethylethyl)-2-hydroxy-3-[(1E)-2-(4-pyridinyl)ethenyl]-Benzaldehyde](/data/chemimg/1373284-30-0_b.png)
![4,4',4''-[borylidynetris(2,3,5,6-tetramethyl-4,1-phenylene)]tris-Pyridine](/data/chemimg/3805600/1046498-57-0.png)
![4,4',4''-[borylidynetris(2,3,5,6-tetramethyl-4,1-phenylene)]tris-Pyridine](/data/chemimg/3805600/1046498-57-0_b.png)
![[1,1',3',1''- Terphenyl] - 3, 3''- dicarboxaldehyde](/data/chemimg/1222784-84-0.png)
![[1,1',3',1''- Terphenyl] - 3, 3''- dicarboxaldehyde](/data/chemimg/1222784-84-0_b.png)
![[1,1':3',1'':3'',1'''-Quaterphenyl]-3,3''',5,5'''-tetracarboxylic acid, 5',5''-bis(1,1-dimethylethyl)-4',6''-dihydroxy-2',2''-dimethyl-, (1''S)-](/data/chemimg/1439272-23-7.png)
![[1,1':3',1'':3'',1'''-Quaterphenyl]-3,3''',5,5'''-tetracarboxylic acid, 5',5''-bis(1,1-dimethylethyl)-4',6''-dihydroxy-2',2''-dimethyl-, (1''S)-](/data/chemimg/1439272-23-7_b.png)
![Phenol, 2-[[[(1R,2R)-2-aminocyclohexyl]amino]methyl]-6-(1,1-dimethylethyl)-4-(4-pyridinyl)-](/data/chemimg/3777500/1448984-97-1.png)
![Phenol, 2-[[[(1R,2R)-2-aminocyclohexyl]amino]methyl]-6-(1,1-dimethylethyl)-4-(4-pyridinyl)-](/data/chemimg/3777500/1448984-97-1_b.png)
![3-Oxa-9-azoniatricyclo[3.3.1.02,4]nonane,7-[(2-hydroxy-2,2-di-2-thienylacetyl)oxy]-9,9-dimethyl-, (1a,2b,4b,5a,7b)-](http://img.cochemist.com/ccimg/186700/186691-13-4.png)
![3-Oxa-9-azoniatricyclo[3.3.1.02,4]nonane,7-[(2-hydroxy-2,2-di-2-thienylacetyl)oxy]-9,9-dimethyl-, (1a,2b,4b,5a,7b)-](http://img.cochemist.com/ccimg/186700/186691-13-4_b.png)
![3-Butenenitrile, 4-phenyl-2-[(trimethylsilyl)oxy]-, (2S,3E)-](http://img.cochemist.com/ccimg/177200/177186-35-5.png)
![3-Butenenitrile, 4-phenyl-2-[(trimethylsilyl)oxy]-, (2S,3E)-](http://img.cochemist.com/ccimg/177200/177186-35-5_b.png)
![Aziridine, 2-(4-bromophenyl)-1-[(4-methylphenyl)sulfonyl]-](http://img.cochemist.com/ccimg/97500/97401-95-1.png)
![Aziridine, 2-(4-bromophenyl)-1-[(4-methylphenyl)sulfonyl]-](http://img.cochemist.com/ccimg/97500/97401-95-1_b.png)
![Aziridine, 2-(4-chlorophenyl)-1-[(4-methylphenyl)sulfonyl]-](http://img.cochemist.com/ccimg/97500/97401-93-9.png)
![Aziridine, 2-(4-chlorophenyl)-1-[(4-methylphenyl)sulfonyl]-](http://img.cochemist.com/ccimg/97500/97401-93-9_b.png)
![Aziridine, 2-(4-methylphenyl)-1-[(4-methylphenyl)sulfonyl]-](http://img.cochemist.com/ccimg/97500/97401-87-1.png)
![Aziridine, 2-(4-methylphenyl)-1-[(4-methylphenyl)sulfonyl]-](http://img.cochemist.com/ccimg/97500/97401-87-1_b.png)
![Benzamide, N-[2-hydroxy-2-(4-methoxyphenyl)ethyl]-, (R)-](http://img.cochemist.com/ccimg/37800/37791-56-3.png)
![Benzamide, N-[2-hydroxy-2-(4-methoxyphenyl)ethyl]-, (R)-](http://img.cochemist.com/ccimg/37800/37791-56-3_b.png)
![Aziridine,1-[(4-methylphenyl)sulfonyl]-2-phenyl-](http://img.cochemist.com/ccimg/24400/24395-14-0.png)
![Aziridine,1-[(4-methylphenyl)sulfonyl]-2-phenyl-](http://img.cochemist.com/ccimg/24400/24395-14-0_b.png)
![Benzamide, N-[(2S)-2-hydroxy-2-(4-methoxyphenyl)ethyl]-](http://img.cochemist.com/ccimg/15800/15779-24-5.png)
![Benzamide, N-[(2S)-2-hydroxy-2-(4-methoxyphenyl)ethyl]-](http://img.cochemist.com/ccimg/15800/15779-24-5_b.png)
![Benzeneacetonitrile, a-[(trimethylsilyl)oxy]-, (S)-](http://img.cochemist.com/ccimg/131400/131350-12-4.png)
![Benzeneacetonitrile, a-[(trimethylsilyl)oxy]-, (S)-](http://img.cochemist.com/ccimg/131400/131350-12-4_b.png)
![Benzeneacetonitrile, a-[(trimethylsilyl)oxy]-, (R)-](http://img.cochemist.com/ccimg/120500/120443-82-5.png)
![Benzeneacetonitrile, a-[(trimethylsilyl)oxy]-, (R)-](http://img.cochemist.com/ccimg/120500/120443-82-5_b.png)
![Benzeneacetonitrile, 4-methoxy-α-[(trimethylsilyl)oxy]-, (αR)-](/data/chemimg/133700/120390-74-1.png)
![Benzeneacetonitrile, 4-methoxy-α-[(trimethylsilyl)oxy]-, (αR)-](/data/chemimg/133700/120390-74-1_b.png)
![Poly[(1,3-dihydro-1,3-dioxo-2H-isoindole-2,5-diyl)thio(1,3-dihydro-1,3-d
ioxo-2H-isoindole-5,2-diyl)-1,4-phenyleneoxy-1,4-phenylene]](http://img.cochemist.com/ccimg/59400/59380-34-6.png)
![Poly[(1,3-dihydro-1,3-dioxo-2H-isoindole-2,5-diyl)thio(1,3-dihydro-1,3-d
ioxo-2H-isoindole-5,2-diyl)-1,4-phenyleneoxy-1,4-phenylene]](http://img.cochemist.com/ccimg/59400/59380-34-6_b.png)
](http://img.cochemist.com/ccimg/27000/26913-06-4.png)
](http://img.cochemist.com/ccimg/27000/26913-06-4_b.png)
![Poly[(1,3-dihydro-1,3-dioxo-2H-isoindole-2,5-diyl)oxy(1,3-dihydro-1,3-dioxo-2H-isoindole-5,2-diyl)-1,4-phenyleneoxy-1,4-phenylene]](http://img.cochemist.com/ccimg/25800/25735-00-6.png)
![Poly[(1,3-dihydro-1,3-dioxo-2H-isoindole-2,5-diyl)oxy(1,3-dihydro-1,3-dioxo-2H-isoindole-5,2-diyl)-1,4-phenyleneoxy-1,4-phenylene]](http://img.cochemist.com/ccimg/25800/25735-00-6_b.png)
![Piperidinium, 4-[(diphenylacetyl)oxy]-1,1-dimethyl-](http://img.cochemist.com/ccimg/81500/81405-11-0.png)
![Piperidinium, 4-[(diphenylacetyl)oxy]-1,1-dimethyl-](http://img.cochemist.com/ccimg/81500/81405-11-0_b.png)
![(S)-(1R,3S,5R,6S)-6-Hydroxy-8-methyl-8-azabicyclo[3.2.1]octan-3-yl 3-hydroxy-2-phenylpropanoate](http://img.cochemist.com/ccimg/55900/55869-99-3.png)
![(S)-(1R,3S,5R,6S)-6-Hydroxy-8-methyl-8-azabicyclo[3.2.1]octan-3-yl 3-hydroxy-2-phenylpropanoate](http://img.cochemist.com/ccimg/55900/55869-99-3_b.png)