AbstractThe silver-catalyzed oxidative C(sp3)−H/P−H cross-coupling of 1,3-dicarbonyl compounds with H-phosphonates, followed by a chemo- and regioselective C(sp3)−C(CO) bond-cleavage step, provided heavily functionalized β-ketophosphonates. This novel method based on a readily available reaction system exhibits wide scope, high functional-group tolerance, and exclusive selectivity.

AbstractThe silver-catalyzed oxidative C(sp3)−H/P−H cross-coupling of 1,3-dicarbonyl compounds with H-phosphonates, followed by a chemo- and regioselective C(sp3)−C(CO) bond-cleavage step, provided heavily functionalized β-ketophosphonates. This novel method based on a readily available reaction system exhibits wide scope, high functional-group tolerance, and exclusive selectivity.

•Novel polymeric nanosphere-supported multifunctional organocatalyst with two catalysts.•Synthesis of optically active molecules with multiple stereocenters in green manner.•Easy renovation and good reusability without significant loss in catalytic performances.Heterogeneous multicomponent/multicatalysed asymmetric organocascade reaction in green manner is a challenging task owing to mass transfer limitation and cooperative catalysis of double or multiple catalysts. In this work, a novel type of nanosphere-supported multifunctional organocatalysts with high catalytic performances was developed towards meeting this challe- nge by the facile emulsion polymerization of organocatalyst (ProTMS or Pro) with styrene and acrylic acid (AA) in aqueous solution. The as-prepared Jorgensen–Hayashi organocatalyst/Brønsted acid-tethered polymeric nanospheres with large surface area, pore volume and high loading capacities of ProTMS and AA catalysts displayed the similar excellent catalytic performances as the corresponding homogeneous counterparts in heterogeneous three-component/triple Michael/Michael/aldol organocascade reaction (38–78%, > 19:1 dr and 95–99%ee) and [4 + 2]-type cycloaddition (76–86%, > 19:1 dr and 90–99%ee). Furthermore, the polymeric nanospheres could be quantitatively recovered from reaction mixture by centrifugation, reused without significant loss in catalytic performances and renovated with the upgraded efficiency in Michael/Michael/aldol organocascade reaction. The research findings of this study provided an important strategy and technology for the large-scale synthesis of optically active molecules with multiple stereocenters in a green manner.Polymeric nanosphere-supported multifunctional organocatalyst promoted complex heterogeneous asymmetric Michael/Michael/aldol organocascade reaction and asymmetric [4 + 2]-type cycloaddition in green manners with good to excellent catalytic performances.Download full-size image

•The covalent immobilization of Maruoka PTCs onto microsphere for the first time•The porous feature of microsphere was responsible for catalytic performance in α-alkylation.•Good reusability was achieved without significant loss of catalytic performances.The covalent immobilization of valuable simplified Maruoka catalyst onto poly(styrene-co-acrylamide)microsphere at different locations was developed for the first time through the copolymerization of Maruoka catalyst-functionalized styrene with styrene and acrylamide cross-linked by EGDMA. It was found the morphology, porous feature of microsphere and the anchor location of Maruoka catalyst were mainly responsible for the catalytic performance in heterogeneous α-alkylation. The catalyst poly[St-co-AA-co-(R)-11] with a rigid framework, where homogeneous (R)-11 was anchored at the 6, 6′-positions of binaphthyl skeleton, possessed the relatively larger surface area (33.5 m2 g− 1) and pore volume (1.27 cm3 g− 1) and displayed high yields (81–96%) and excellent enantioselectivities (96–97%ee) in enantioselective α-alkylation.The covalent immobilization of valuable Maruoka catalyst onto poly(styrene-co-acrylamide) microsphere was developed for the first time through the copolymerization of styrene-functionalized Maruoka catalyst with styrene and acrylamide by means of suspension polymerization.Download high-res image (221KB)Download full-size image

Fe3O4 MNP-supported 9-amino(9-deoxy)epi-quinidine (Fe3O4/PVP@QDNH2) with core–shell morphology and a high loading capacity of QDNH2 (0.60 mmol g−1) was prepared by an available one-pot method through the first homogeneous radical-mediated thiol–ene click reaction of QDNH2 with 3-mercaptotrimethoxysilane (MPTMS) and then hydrolysis of –Si(OCH3)3 on the surface of Fe3O4/PVP MNPs, and exhibited the good isolated yields (75–89%), excellent diastereoselectivities (syn/anti = 95–98/2–5) and remarkable enantioselectivities (95–98% ee syn) in the α-amination of (2R,3S)-2-methyl-3-nitro-4-phenylbutyraldehyde and its derivatives with di-iso-propyl azodicarboxylate (DIAD). Fortunately, the good diastereoselectivity (syn/anti = 88/12) and excellent enantioselectivity (95% ee syn) in the fifth run could be achieved in 75% yield.

A new supported (S)-diphenylprolinol trimethylsilyl ether (Fe3O4/PVP@SiO2/ProTMS) using polyvinylpyrrolidone (PVP)-modified MNPs Fe3O4 as a support was prepared via one-pot surface-modification, and exhibited high yield (93–99%), excellent diastereoselectivities (syn/anti = 81–96:19–4) and enantioselectivities (95–98% ee) in the asymmetric Michael addition of propanal to various nitroalkenes. TGA, XRD, IR, SEM, TEM, elemental analysis and N2 adsorption–desorption isotherm demonstrated that the adsorption of PVP onto MNPs Fe3O4 resulted in the spectacular change in the chemical composition, surface morphology and pore structure of Fe3O4/PVP@SiO2/ProTMS. The catalyst could be easily separated from the reaction by an external magnet and reused for ten times with high yields (77–99%) and unchanged excellent stereoselectivities (97–98% ee and syn/anti = 96/4) in the Michael addition for the first time.

A novel type of silica gel-supported cinchona alkaloid-based quaternary ammonium salt was prepared by available one-pot synthesis for the first time through the free radical addition of the sulfhydryl group of 3-mercaptopropyltrimethoxysilane to an exocyclic carbon–carbon double bond in N-(2-cyanobenzyl)-O(9)-allyl-cinchonidinium bromide and subsequent hydrolysis of trimethoxysilane. In the α-alkylation of N-(diphenylmethylene)glycine tert-butyl ester with alkyl halides, it was found that the various substituted benzyl bromides, both with electron-withdrawing (–CF3 and –F) and electron-donating (–CH3) substituents, afforded the corresponding α-alkylation products with moderate to excellent enantioselectivities (76.0–96.9% ee) in high yields (80–96%). However, allyl bromides gave poor yields (10–50%) and enantioselectivities (52.0–67.1% ee). After completion of the α-alkylation reaction, the silica gel-supported chiral phase-transfer catalyst was readily recovered in quantitative yield by filtration and reused for five consecutive runs without significant loss in the catalytic performance.

A new class of 9-amino-(9-deoxy)cinchona alkaloid-derived chiral phase-transfer catalysts bearing amino groups was developed by using known cinchona alkaloids as the starting materials. Due to the transformation of the 9-hydroxyl group into a 9-amino functional group, the catalytic performances were significantly improved in comparison with the corresponding first generation phase-transfer catalysts, and excellent yields (92–99%) and high enantioselectivities (87–96% ee) were achieved in the benchmark asymmetric α-alkylation of glycine Schiff base. Based on the special contribution of the amino group to the high yield and enantioselectivity, the possible catalytic mechanism was conjectured.

In this paper, a novel type of efficient, magnetically recoverable magnetic nanoparticles (MNPs)-supported 9-amino-9-deoxy-epicinchonidine organocatalysts were prepared through a facile co-precipitation method using phosphonic acid (–PO3H2) as an anchor point. These MNPs-supported organocatalysts possessed the high and tunable loading capacities of an organocatalyst (0.18–0.52 mmol g−1), 2–25 nm regular mesopores and 10.6–44.06 emu g−1 saturated magnetization. In the catalytic asymmetric aldol reactions of cyclohexanone with various o, m and p-substituted benzaldehydes in water, the aromatic aldehydes with electron-withdrawing substituents including-NO2, X and –CN afforded the relevant aldol adducts in excellent yields (86–100%) and steroselectivities (anti/syn = 82–98/18–2 and 93–98%ee anti). Moderate to good yields (36–97%) and steroselectivities (anti/syn = 82–96/18–4 and 75–97%ee anti) for the aromatic aldehydes with strong electron-donating substituents (–CH3 and –OCH3) were also satisfactorily achieved. Futhermore, these MNPs-supported organocatalysts could be quantitatively recovered from the reaction mixture using an external magnet, and reused six times with excellent catalytic performance (93%, anti/syn = 89/11 and 96%ee anti). Meanwhile, MNPs-supported organocatalysts, prepared by the surface-modification method, were investigated in detail as comparative samples.

In this paper, the asymmetric transfer hydrogenation of unsymmetrical benzils with m, p-substituents was conducted with a substrate/catalyst molar ratio of 100 at 40 °C for 24 h to produce (S,S)-hydrobenzoins in good yields (76.2% to 97.1%) with high diastereomeric (syn/anti = 10.8 to 29.7/1) and enantiomeric purities (86.1%ee syn to 98.9%ee syn). Unfortunately, the unsymmetrical benzils with the o-substituents such as electron-donating (R = CH3, OCH3) and electron-withdrawing groups (R = F, Cl, CF3) resulted in poor yields (0% to 31.2%), even at 40 °C for 72 h. These products had inefficient diastereoselectivities (syn/anti = 1.5 to 5.0/1) caused by steric effects. Furthermore, the results of a dynamic–kinetic study were used to propose a plausible reaction pathway of unsymmetrical benzil using 3-methoxy-1,2-diphenyl ethanedione as an example.

Photoresponsive surface molecular imprinting polymer (SMIP) microspheres were synthesized on silica microspheres by surface polymerization using a water-soluble azobenzene-containing 4-[(4-methacryloyloxy)phenylazo]benzenesulfonic acid as the functional monomer. The SMIP microspheres displayed good photoresponsive properties and specific affinity towards bisphenol A (BPA) with high recognition ability (maximal adsorption capacity: 6.96 μmol g−1) and fast binding kinetics (binding constant: 2.47 × 104 M−1) in aqueous media. Upon alternate irradiation at 365 and 440 nm, the SMIP microspheres could quantitatively bind and release BPA. Analytical application of the SMIP microspheres for the detection of trace BPA concentration in mineral water and tap water has been carried out successfully, and therefore a simple and quick detection method for trace BPA in the environment was established.

Four exotic chiral organocatalysts, 9-amino-(9-deoxy) cinchona alkaloids with (8S, 9R) and (8R, 9S)-configurations, were conveniently synthesized for the first time in 27–72% total yields through two conversions of configuration at the 9-stereogenic centers of commercially available cinchona alkaloids.Four exotic chiral organocatalysts, 9-amino-(9-deoxy) cinchona alkaloids with (8S, 9R) and (8R, 9S)-configurations, were conveniently synthesized for the first time in 27%–72% total yields through two conversions of configuration at the 9-stereogenic centers of commercially available cinchona alkaloids.

A novel type of phosphonate-containing polystyrene copolymers 1a–e bearing an N′-alkylated TsDPEN chiral ligand and double-stranded polystyrene chains were prepared for the first time using simple radical copolymerization of 1-phosphonate styrene with (R,R)-N′-4′-vinylbenzyl-N-4-vinylbenzenesulfonyl-1,2-diphenylethylene-1,2-diamine. Through the coprecipitation of their supported Ru polystyrene copolymers 2a–e and NaH2PO4 with ZrOCl2, pillared hybrid zirconium phosphate–phosphonate-anchored Ru catalysts 3a–e and 4d11–d55 were obtained as heterogeneous catalysts suitable for aqueous asymmetric transfer hydrogenation. In the aqueous asymmetric transfer hydrogenation of aromatic ketones, the anchored Ru catalysts showed good catalytic activities, chemoselectivities (∼100%), and enantioselectivities (73.6% ee to 95.6% ee). The Ru catalysts retained their catalytic properties even at the fifth recycle time (92.2% conv., 92.1% ee). However, corresponding supported Ru catalyst 3d′ resulted in disappointing reusability because of the loss of ruthenium in every recycle process. The conversions of aromatic ketones were closely related to the o-, m- or p-positions of the substituents on the aromatic ring caused by shape-selective matching.

A series of phosphonate-containing copolystyrenes with chiral ligand (1R,2R)-(+)-N1-toluenesulfonyl-1,2-diphenylethylene-1,2-diamine were prepared by radical copolymerization. The supported Ru catalysts with excellent catalytic performances (94–98% yields, 93.9–97.8% ee and 100% chemoselectivity) in aqueous asymmetric transfer hydrogenation could be easily recycled by centrifugal separation.

Novel and homogeneous zirconium phosphonate-supported Pd catalysts with modest BET surface areas (25.6 and 24.7 m2 g−1), high pore volumes (0.39 and 0.73 cc g−1) and nano-sized pores (1–10 nm) were prepared by embedding Na2PdCl4 particles in an organosoluble, porous and layered zirconium phosphonate with a filiform architecture structure for the first time. In the homogeneous palladium-catalyzed Suzuki coupling reaction at room temperature, various substituted benzene bromides with phenylboronic acids were smoothly converted into corresponding biphenyl compounds (82–97% yields), even in cases of electron–rich derivatives. These supported homogeneous Pd catalysts could be quantitatively recovered by using a solid/liquid separation technique and be highly active without loss of catalytic activity in three consecutive runs.

In the current study, a convenient and simple way is presented to synthesize a novel type of supported heterogeneous organocatalyst in 21–81% yield by the copolymerization of 9-amino-9-deoxy-epi-cinchonine organocatalyst with acrylonitrile using AIBN as radical initiator. The chemical compositions (x/y) and weight-average molecular weights of copolymers 1a–d were determined by 1H NMR and GPC analysis respectively. Their porous and layered structure, and surface morphology were characterized by nitrogen adsorption–desorption, XRD and TEM. In the asymmetric aldol addition of p-nitrobenzaldehyde to cyclohexanone and 1-hydroxy-2-propanone in water, all the supported organocatalysts 1a–d afforded excellent isolated yields (90.2–94.7%) and stereoselectivities (96.8–97.8%ee anti, anti/syn = 91/9). The highest catalytic property (96% yield, anti/syn = 90/10 and 99%ee anti) in water as the sole solvent was achieved under the optimized conditions. Compared with cyclohexanone, cyclopentanone and acetone showed the less desired enantioselectivities in the same aldol reactions. At the end of the aldol reaction, the copolymer-supported organocatalyst 1a was readily recovered in 95–98% yield from reaction mixture by simple filtration using an organic membrane. Even in the fifth run, there was no significant loss in catalytic activity and stereocontrol (94.3% yield, 97.2%ee anti, anti/syn = 90/10). After continuous reuse five times, there was some drop in catalytic activity and stereoselectivity.

A series of novel porous zirconium phosphonate-supported 9-amino-9-deoxy-epi-cinchonidines of general formulae Zr(OH)4−2x(O3PR)x·nH2O and Zr(HPO4)2−x(O3PR)x·nH2O with the different arm chain lengths (n = 2–6) and mean diameters of approximately 20–40 nm have been prepared as heterogeneous organocatalysts. The different microtextures of zirconium phosphonates were also obtained by using template guest molecules, such as Et3N, NaH2PO4 and sodium dodecyl benzene sulfonate. In the heterogeneous asymmetric aldol addition of p-nitrobenzaldehyde to cyclohexanone, excellent catalytic properties were achieved, especially in an aqueous medium. After completing the reaction, those zirconium phosphonate-supported 9-amino-9-deoxy-epi-cinchonidine organocatalysts could be readily recovered in quantitative yield by centrifugation or filtration, and reused for five consecutive runs without significant loss in catalytic performance. In particular, due to the steric confinement effect of the inorganic backbone, the single different configuration among possible four stereo-isomers in aldol adducts were favorably obtained, respectively depending on the interaction between the o-, m- or p-position of nitrobenzaldehyde and the backbone, which was never observed in homogeneous aldol addition.

In this article, we report the synthesis, structure, morphologies, and asymmetric catalytic properties of a series of novel organosoluble zirconium phosphonate nanocomposites and their supported chiral ruthenium catalysts, which have a good organosolubility (0.1–0.5 g mL−1) in various solvents and mesoporous, filiform, and layered structures. Due to the organosoluble properties in various organic solvents, the first homogenization of zirconium phosphonate-supported catalyst was realized in the field of catalysis. In the asymmetric hydrogenation of substituted α-ketoesters, enantioselectivities (74.3–84.7% ee) and isolated yields (86.7–93.6%) were higher than the corresponding homogeneous Ru(p-cymene)(S-BINAP)Cl2 due to the confinement effect caused by the remaining mesopores in the backbone of the zirconium phosphonate. After completing the reaction, the supported catalyst can be readily recovered in quantitative yield by adding cyclohexane and centrifugation, and reused for five consecutive runs without significant loss in catalytic activity.

A novel type of organosoluble and filiform zirconium phosphonate with a layered mesoporous backbone functionalized with hydroxyl and amino groups was prepared by the reaction of a functionalized phosphoric acid with ZrOCl2·8H2O. These filiform zirconium phosphonates has good solubility (0.21–0.71 g mL−1) in certain organic solvents (such as toluene, chloroform, tetrahydrofuran and ethyl acetate), are immiscible in some other solvents (hexane, cyclohexane, petroleum ether and ethanol), and can be recovered from organic solvents in high yield (95–100%) by precipitation.

(1R, 2S)-(−)-2-amino-1, 2-diphenylethanol and (1S, 2R)-(+)-2-amino-1, 2-diphenylethanol had been immobilized on the layered titanium phosphonates 4a–d and hybrid titanium phosphonates 5a–c in spheroid form with interlayer space 20.845–19.407 Å which can be used as heterogeneous catalysts in the enantioseletive addition of diethylzinc to benzaldehyde to obtain optically active (R)-or (S)-1-phenylpropan-1-ol for the first time. It was shown that the titanium phosphonate 4a led to active heterogeneous catalysis for asymmetric additions of diethylzinc to benzaldehydes in 88.5% yield and ee value of up to 40.8% which decreased at 16% ee lower than corresponding chiral ligand in homogeneous asymmetric catalysis. AFM showed that the distribution of 1,2-dipenyl-2-aminoethanol organic moieties on the surface of titanium phosphonates irregularly lined like flow mark.

•The in-situ preparation of cooperative organocatalysts tethered on aluminium phosphonate.•Aldol addition and double-Michael organocascade in green manner.•Good reusability of organocatalyst without significant loss of catalytic performances.Novel aluminium phosphonate-supported organocatalysts performing the cooperative catalysis of enamine-acid and enamine/iminium-acid were easily prepared by means of the direct and rapid precipitation of 9-amino(9-deoxy)epi-cinchona alkaloid-derived phosphonate with sodium aluminate. The heterogeneous cooperative organocatalysts with multiple functionality efficiently promoted the green aqueous asymmetric aldol addition of cyclohexanone to o, m, p-substituted benzaldehydes bearing electron-withdrawing substituents (65–98% yield, anti/syn = 82:18–95:5 and 92–98%ee anti) and double-Michael of α, β-unsaturated ketones to aromatic nitroalkenes (36–85% yield, trans/cis = 86:14–97:3 and 78–96%ee trans). These catalysts could be quantitatively recovered from reaction mixture by centrifugation and reused without significant loss of catalytic performances for aldol addition in the tenth run (95%, anti/syn = 91:9 and 92%ee anti) and double-Michael cascade reaction in the fifth run (62%, trans/syn = 89:11 and 87%ee trans). Furthermore, the arm length (n) and H+ exchange capacity resulted from POH defects had significant effects on the cooperative catalysis of 9-amino(9-deoxy)epi-cinchona alkaloid and Brønsted acid.Download full-size imageHeterogeneous cooperative catalysts tethered on the backbone of aluminium phosphonates cooperatively catalyzed asymmetric aldol addition and double-Michael cascade reaction in green manner.

•Zirconium phosphonate-supported ruthenium catalysts were homogenized.•Unsymmetrical benzils were hydrogenated in excellent catalytic performance.•The good reusability with 97.0% conv., 95.6% syn, syn/anti = 20.7 in the fifth run.In this article, a successful design on translating a heterogeneous catalysis of chiral zirconium phosphonate-supported ruthenium catalyst into a homogeneous system was developed by the covalent attachment of chiral (R,R)-1,2-diphenyl-ethylenediamine [(R,R)-DPEN] into the backbone of zirconium phosphonate with the different arm lengths (n = 2, 4, 6) and immobilization of [RuCl2(p-cymene)]2. Their catalytic performances in the homogeneous asymmetric transfer hydrogenation of unsymmetrical benzils with m- and p-substituents were enhanced, and the excellent activities (>97.1% conv.), diastereomeric and enantiomeric purities (syn/anti = 11.0–29.4, 91.8–99.2%ee syn) were achieved. These homogeneous supported Ru catalysts could be quantitatively and readily recovered by addition of ethyl acetate and centrifugation by solid/liquid separation, and be reused for five times without significant loss of their catalytic performances with 97.0% conv., 95.6% syn and syn/anti = 20.7.Download high-res image (209KB)Download full-size image

A series of novel organosoluble zirconium phosphonate nanocomposites and their supported ruthenium catalysts with an organosoluble (20–142 mg mL− 1), mesoporous and layered structure were prepared. Due to organosolubilities in various organic solvents, the homogenization of the zirconium phosphonate-supported catalyst was realized in the asymmetric hydrogenation of ethyl pyruvate, in which supported ruthenium catalysts possessed higher conversion, isolated yield and enantioselectivity than corresponding homogeneous Ru(p-cymene)(S-Binap)Cl2 owing to site-isolation and confinement effect. After completing the reaction, the supported ruthenium catalyst can be recovered readily and quantitatively by addition of a poor solvent and centrifugation, and reused for five consecutive runs without significant loss in catalytic properties.Download full-size imageResearch Highlights►Organosoluble zirconium phosphonate-supported ruthenium catalysts were prepared. ►A catalytic reaction can be run under homogeneous conditions in organic solvents. ►Supported ruthenium catalyst was quantitatively recovered by solid/liquid separation. ►Better catalytic properties were observed owing to confinement effect.

Novel and homogeneous zirconium phosphonate-supported Pd catalysts with modest BET surface areas (25.6 and 24.7 m2 g−1), high pore volumes (0.39 and 0.73 cc g−1) and nano-sized pores (1–10 nm) were prepared by embedding Na2PdCl4 particles in an organosoluble, porous and layered zirconium phosphonate with a filiform architecture structure for the first time. In the homogeneous palladium-catalyzed Suzuki coupling reaction at room temperature, various substituted benzene bromides with phenylboronic acids were smoothly converted into corresponding biphenyl compounds (82–97% yields), even in cases of electron–rich derivatives. These supported homogeneous Pd catalysts could be quantitatively recovered by using a solid/liquid separation technique and be highly active without loss of catalytic activity in three consecutive runs.

A novel type of phosphonate-containing polystyrene copolymers 1a–e bearing an N′-alkylated TsDPEN chiral ligand and double-stranded polystyrene chains were prepared for the first time using simple radical copolymerization of 1-phosphonate styrene with (R,R)-N′-4′-vinylbenzyl-N-4-vinylbenzenesulfonyl-1,2-diphenylethylene-1,2-diamine. Through the coprecipitation of their supported Ru polystyrene copolymers 2a–e and NaH2PO4 with ZrOCl2, pillared hybrid zirconium phosphate–phosphonate-anchored Ru catalysts 3a–e and 4d11–d55 were obtained as heterogeneous catalysts suitable for aqueous asymmetric transfer hydrogenation. In the aqueous asymmetric transfer hydrogenation of aromatic ketones, the anchored Ru catalysts showed good catalytic activities, chemoselectivities (∼100%), and enantioselectivities (73.6% ee to 95.6% ee). The Ru catalysts retained their catalytic properties even at the fifth recycle time (92.2% conv., 92.1% ee). However, corresponding supported Ru catalyst 3d′ resulted in disappointing reusability because of the loss of ruthenium in every recycle process. The conversions of aromatic ketones were closely related to the o-, m- or p-positions of the substituents on the aromatic ring caused by shape-selective matching.

A series of novel porous zirconium phosphonate-supported 9-amino-9-deoxy-epi-cinchonidines of general formulae Zr(OH)4−2x(O3PR)x·nH2O and Zr(HPO4)2−x(O3PR)x·nH2O with the different arm chain lengths (n = 2–6) and mean diameters of approximately 20–40 nm have been prepared as heterogeneous organocatalysts. The different microtextures of zirconium phosphonates were also obtained by using template guest molecules, such as Et3N, NaH2PO4 and sodium dodecyl benzene sulfonate. In the heterogeneous asymmetric aldol addition of p-nitrobenzaldehyde to cyclohexanone, excellent catalytic properties were achieved, especially in an aqueous medium. After completing the reaction, those zirconium phosphonate-supported 9-amino-9-deoxy-epi-cinchonidine organocatalysts could be readily recovered in quantitative yield by centrifugation or filtration, and reused for five consecutive runs without significant loss in catalytic performance. In particular, due to the steric confinement effect of the inorganic backbone, the single different configuration among possible four stereo-isomers in aldol adducts were favorably obtained, respectively depending on the interaction between the o-, m- or p-position of nitrobenzaldehyde and the backbone, which was never observed in homogeneous aldol addition.

A novel type of organosoluble and filiform zirconium phosphonate with a layered mesoporous backbone functionalized with hydroxyl and amino groups was prepared by the reaction of a functionalized phosphoric acid with ZrOCl2·8H2O. These filiform zirconium phosphonates has good solubility (0.21–0.71 g mL−1) in certain organic solvents (such as toluene, chloroform, tetrahydrofuran and ethyl acetate), are immiscible in some other solvents (hexane, cyclohexane, petroleum ether and ethanol), and can be recovered from organic solvents in high yield (95–100%) by precipitation.

A new class of 9-amino-(9-deoxy)cinchona alkaloid-derived chiral phase-transfer catalysts bearing amino groups was developed by using known cinchona alkaloids as the starting materials. Due to the transformation of the 9-hydroxyl group into a 9-amino functional group, the catalytic performances were significantly improved in comparison with the corresponding first generation phase-transfer catalysts, and excellent yields (92–99%) and high enantioselectivities (87–96% ee) were achieved in the benchmark asymmetric α-alkylation of glycine Schiff base. Based on the special contribution of the amino group to the high yield and enantioselectivity, the possible catalytic mechanism was conjectured.

In the current study, a convenient and simple way is presented to synthesize a novel type of supported heterogeneous organocatalyst in 21–81% yield by the copolymerization of 9-amino-9-deoxy-epi-cinchonine organocatalyst with acrylonitrile using AIBN as radical initiator. The chemical compositions (x/y) and weight-average molecular weights of copolymers 1a–d were determined by 1H NMR and GPC analysis respectively. Their porous and layered structure, and surface morphology were characterized by nitrogen adsorption–desorption, XRD and TEM. In the asymmetric aldol addition of p-nitrobenzaldehyde to cyclohexanone and 1-hydroxy-2-propanone in water, all the supported organocatalysts 1a–d afforded excellent isolated yields (90.2–94.7%) and stereoselectivities (96.8–97.8%ee anti, anti/syn = 91/9). The highest catalytic property (96% yield, anti/syn = 90/10 and 99%ee anti) in water as the sole solvent was achieved under the optimized conditions. Compared with cyclohexanone, cyclopentanone and acetone showed the less desired enantioselectivities in the same aldol reactions. At the end of the aldol reaction, the copolymer-supported organocatalyst 1a was readily recovered in 95–98% yield from reaction mixture by simple filtration using an organic membrane. Even in the fifth run, there was no significant loss in catalytic activity and stereocontrol (94.3% yield, 97.2%ee anti, anti/syn = 90/10). After continuous reuse five times, there was some drop in catalytic activity and stereoselectivity.

In this article, we report the synthesis, structure, morphologies, and asymmetric catalytic properties of a series of novel organosoluble zirconium phosphonate nanocomposites and their supported chiral ruthenium catalysts, which have a good organosolubility (0.1–0.5 g mL−1) in various solvents and mesoporous, filiform, and layered structures. Due to the organosoluble properties in various organic solvents, the first homogenization of zirconium phosphonate-supported catalyst was realized in the field of catalysis. In the asymmetric hydrogenation of substituted α-ketoesters, enantioselectivities (74.3–84.7% ee) and isolated yields (86.7–93.6%) were higher than the corresponding homogeneous Ru(p-cymene)(S-BINAP)Cl2 due to the confinement effect caused by the remaining mesopores in the backbone of the zirconium phosphonate. After completing the reaction, the supported catalyst can be readily recovered in quantitative yield by adding cyclohexane and centrifugation, and reused for five consecutive runs without significant loss in catalytic activity.

A novel type of silica gel-supported cinchona alkaloid-based quaternary ammonium salt was prepared by available one-pot synthesis for the first time through the free radical addition of the sulfhydryl group of 3-mercaptopropyltrimethoxysilane to an exocyclic carbon–carbon double bond in N-(2-cyanobenzyl)-O(9)-allyl-cinchonidinium bromide and subsequent hydrolysis of trimethoxysilane. In the α-alkylation of N-(diphenylmethylene)glycine tert-butyl ester with alkyl halides, it was found that the various substituted benzyl bromides, both with electron-withdrawing (–CF3 and –F) and electron-donating (–CH3) substituents, afforded the corresponding α-alkylation products with moderate to excellent enantioselectivities (76.0–96.9% ee) in high yields (80–96%). However, allyl bromides gave poor yields (10–50%) and enantioselectivities (52.0–67.1% ee). After completion of the α-alkylation reaction, the silica gel-supported chiral phase-transfer catalyst was readily recovered in quantitative yield by filtration and reused for five consecutive runs without significant loss in the catalytic performance.