A general method for selective ortho C–H arylation of ketone, with boron reagent enabled by rhodium complexes with excellent yields, is developed. The transformation is characterized by the use of air-stable Rh catalyst, high monoarylation selectivity, and excellent yields of most of the substrates.

A range of Rh(III)-catalyzed ortho-C–H functionalizations have been developed; however, extension of this reactivity to remote C–H functionalizations through large-ring rhodacyclic intermediates has yet to be demonstrated. Herein we report the first example of the use of a U-shaped nitrile template to direct Rh(III)-catalyzed remote meta-C–H activation via a postulated 12-membered macrocyclic intermediate. Because the ligands used for Rh(III) catalysts are significantly different from those of Pd(II) catalysts, this offers new opportunities for future development of ligand-promoted meta-C–H activation reactions.

A range of Rh(III)-catalyzed ortho-C–H functionalizations have been developed; however, extension of this reactivity to remote C–H functionalizations through large-ring rhodacyclic intermediates has yet to be demonstrated. Herein we report the first example of the use of a U-shaped nitrile template to direct Rh(III)-catalyzed remote meta-C–H activation via a postulated 12-membered macrocyclic intermediate. Because the ligands used for Rh(III) catalysts are significantly different from those of Pd(II) catalysts, this offers new opportunities for future development of ligand-promoted meta-C–H activation reactions.

AbstractLigand development for rhodium(III)-catalyzed C−H activation reactions has largely been limited to cyclopentadienyl (Cp) based scaffolds. 2-Methylquinoline has now been identified as a feasible ligand that can coordinate to the metal center of Cp*RhCl to accelerate the cleavage of the C−H bond of N-pentafluorophenylbenzamides, providing a new structural lead for ligand design. The compatibility of this reaction with secondary free amines and anilines also overcomes the limitations of palladium(II)-catalyzed C−H amination reactions.

A new one-pot synthesis of C2-hydroxypropyl-substituted imidazolinium salts via the ring opening of tetrahydrofuran (THF) with N,N′-disubstituted diamines has been developed. Preliminary studies of the reaction mechanism suggest the CO2-promoted oxidative ring opening of THF followed by Hg(II)-mediated oxidation of an imidazolidine intermediate. These novel C2-substituted imidazolinium salts have shown to be active catalysts for the aza-Diels–Alder reactions.

Excess and deficiency of iron(III) and antibiotics from normal permissible limits will induce serious disorders, so their detection is important but challenging. In this work, by introducing a new amino triazole ligand N1-(4-(1H-1,2,4-triazole-1-yl)benzyl)-N1-(2-aminoethyl)ethane-1,2-diamine (L), a series of Cd(II)-based metal–organic frameworks (MOFs) [Cd3(BDC)3(DMF)2] (1), [Cd(L)(BDC)]2·2DMF·H2O (2), [NaCd2(L)(BDC)2.5]·9H2O (3), [Cd2(L)(2,6-NDC)2]·DMF·5H2O (4) and [Cd2(L)(BPDC)2]·DMF·9H2O (5) were synthesized. MOFs 1, 2 and 3 obtained under the same conditions with the same auxiliary ligand (H2BDC) but different amounts of alkali (NaOH) show distinct 3D, 1D and 3D framework structures, respectively, in which L and BDC2− exhibit varied coordination modes. 4 and 5 with 3D structures were isolated by using longer auxiliary ligands of 2,6-H2NDC and H2BPDC. The porosity and excellent fluorescence performance of 3, 4 and 5 make them potential luminescent sensors for Fe(III) and antibiotics. The results show that 3, 4 and 5 represent high sensitivity for the detection of Fe(III) ions with detection limits of 155 ppb for 3, 209 ppb for 4 and 297 ppb for 5 due to the existence of open channels and chelating NH2 sites. In addition, the strong emissions of 3, 4 and 5 can be quenched efficiently by trace amounts of NFs (nitrofurazone, NZF; nitrofurantoin, NFT; furazolidone, FZD) antibiotics even in the presence of other competing antibiotics such as β-lactams (penicillin, PCL). They are responsive to NZF with detection limits of 162 ppb for 3, 75 ppb for 4 and 60 ppb for 5.

•Zn(II) and Ni(II) frameworks with mixed organic ligands have been obtained.•The frameworks show different 2D network and 3D structures.•Sorption properties of the frameworks were investigated.Zinc(II) and nickel(II) frameworks [Zn2(L)(BTC)(NO3)]·H2O·2CH3CN (1), [Ni2(L)(H2O)3(HBTC)2]·3.6H2O (2), [Ni(L)(H2O)2](BPDC)·2H2O (3), [Ni(L)(H2O)(BPDC)]·4H2O (4) and [Ni2(L)(MeOH)4(BPDC)2]·2H2O (5) were synthesized by reactions of corresponding metal salts with 3,3′,5,5′-tetra(1H-imidazol-1-yl)-1,1′-biphenyl (L) and multicarboxylic acids of 1,3,5-benzenetricarboxylic acid (H3BTC), 4,4′-biphenyldicarboxylic acid (H2BPDC). Complex 1 is a 2-fold interpenetrating 3D net, while 2 is a 2D network with infinite 1D hinged Ni(II)-L chains linked by HBTC2− ligands. 3, 4 and 5 were obtained by using different molar ratios of L, H2BPDC and Ni(II) salt, and found to show different 2D network structures in which the numbers of coordinated carboxylate groups of BPDC2− are 0, 1 and 2, respectively. Sorption properties of 1–5 were investigated.

Rhodium(III)-catalyzed C–H arylation of arenes with phenylboronic acid pinacol esters has been achieved using a readily removable N-pentafluorophenylbenzamide directing group for the first time. The use of a bidentate phosphine ligand (Binap) significantly increased the yield of the cross-coupling of C–H bonds with organoboron reagents.

Multidimensional supramolecular assemblies based on cucurbit[n]uril (n = 6 or 7) were constructed via the outer-surface interactions of cucurbit[n]urils with the polyaromatic compound 4,4′,4″-benzene-1,3,5-triyl-tribenzoate as a structure-directing agent. Most impressively, the cucurbit[6]uril-based assembly exhibits high selectivity for capture of cesium cations among the common alkali metal ions in a basic medium and releases the cesium cations under acidic conditions. This reversible process enables possible applications in cesium cation capture.

Three new metal–organic frameworks (MOFs) {[Zn(L)(HCOO)(H2O)]·H2O}n (1), {Cd(L)2}n (2) and {Co(L)(BDC)0.5(H2O)}n (3) [HL = 3,5-di(pyridine-4-yl)benzoic acid, H2BDC = 1,4-benzenedicarboxylic acid] were synthesized by hydro/solvothermal reactions and characterized by elemental analysis, thermogravimetric analysis, IR spectroscopy, powder and single crystal X-ray diffraction. Complex 1 is a two-dimensional (2D) network with {63} topology, which is further assembled into a three-dimensional (3D) supramolecular architecture through hydrogen bonding interactions. Complex 2 is a 2-fold interpenetrating 3D framework with a point (Schläfli) symbol of {63}{67·83}, while 3 is a 3D net formed by interpenetration of 2D bilayers (2D + 2D → 3D) with a point (Schläfli) symbol of {63}{66}. Selective and hysteretic sorption of carbon dioxide (CO2) was found for 3 at 195 K, and the photoluminescence properties of 1 and 2 were investigated.

Excess and deficiency of iron(III) and antibiotics from normal permissible limits will induce serious disorders, so their detection is important but challenging. In this work, by introducing a new amino triazole ligand N1-(4-(1H-1,2,4-triazole-1-yl)benzyl)-N1-(2-aminoethyl)ethane-1,2-diamine (L), a series of Cd(II)-based metal–organic frameworks (MOFs) [Cd3(BDC)3(DMF)2] (1), [Cd(L)(BDC)]2·2DMF·H2O (2), [NaCd2(L)(BDC)2.5]·9H2O (3), [Cd2(L)(2,6-NDC)2]·DMF·5H2O (4) and [Cd2(L)(BPDC)2]·DMF·9H2O (5) were synthesized. MOFs 1, 2 and 3 obtained under the same conditions with the same auxiliary ligand (H2BDC) but different amounts of alkali (NaOH) show distinct 3D, 1D and 3D framework structures, respectively, in which L and BDC2− exhibit varied coordination modes. 4 and 5 with 3D structures were isolated by using longer auxiliary ligands of 2,6-H2NDC and H2BPDC. The porosity and excellent fluorescence performance of 3, 4 and 5 make them potential luminescent sensors for Fe(III) and antibiotics. The results show that 3, 4 and 5 represent high sensitivity for the detection of Fe(III) ions with detection limits of 155 ppb for 3, 209 ppb for 4 and 297 ppb for 5 due to the existence of open channels and chelating NH2 sites. In addition, the strong emissions of 3, 4 and 5 can be quenched efficiently by trace amounts of NFs (nitrofurazone, NZF; nitrofurantoin, NFT; furazolidone, FZD) antibiotics even in the presence of other competing antibiotics such as β-lactams (penicillin, PCL). They are responsive to NZF with detection limits of 162 ppb for 3, 75 ppb for 4 and 60 ppb for 5.