(Indenyl)rhodacarboranes. Electronic versus steric effects on the conformation of cyclic ligands

(Indenyl)rhodacarboranes 1,2-R2-3-(η5-indenyl)-3,1,2-RhC2B9H9 (2a: R = H; 2b: R = Me) and 3-(η5-indenyl)-4-SMe-3,1,2-RhC2B9H10 (3) were synthesized by reactions of the iodide complex [(η5-indenyl)RhI2]n (1b) with Tl[Tl(η-7,8-R2-7,8-C2B9H9)] or Tl[9-SMe2-7,8-C2B9H10]. The formation of 3 is accompanied by monodemethylation of the SMe2 substituent. The structures of rhodacarboranes 2b, 3 and the half-sandwich complex (η5-indenyl)RhBr2(dmso) were determined by X-ray diffraction. Rhodacarborane 2b has the sterically unfavorable eclipsed cisoid conformation, in which the bridgehead carbon atoms of the indenyl ligand are arranged close to the carborane cage carbon atoms. The thermal stability of conformers for 2b was analyzed by the DFT calculations. © 2018 Elsevier B.V

(Indenyl)rhodacarboranes. Electronic versus steric effects on the conformation of cyclic ligands

(Indenyl)rhodacarboranes 1,2-R2-3-(η5-indenyl)-3,1,2-RhC2B9H9 (2a: R = H; 2b: R = Me) and 3-(η5-indenyl)-4-SMe-3,1,2-RhC2B9H10 (3) were synthesized by reactions of the iodide complex [(η5-indenyl)RhI2]n (1b) with Tl[Tl(η-7,8-R2-7,8-C2B9H9)] or Tl[9-SMe2-7,8-C2B9H10]. The formation of 3 is accompanied by monodemethylation of the SMe2 substituent. The structures of rhodacarboranes 2b, 3 and the half-sandwich complex (η5-indenyl)RhBr2(dmso) were determined by X-ray diffraction. Rhodacarborane 2b has the sterically unfavorable eclipsed cisoid conformation, in which the bridgehead carbon atoms of the indenyl ligand are arranged close to the carborane cage carbon atoms. The thermal stability of conformers for 2b was analyzed by the DFT calculations. © 2018 Elsevier B.V

Indenyl Rhodium Complexes with Arene Ligands: Synthesis and Application for Reductive Amination

An efficient protocol for synthesis of indenyl rhodium complexes with arene ligands has been developed. The hexafluoroantimonate salts [(σ5-indenyl)Rh(arene)](SbF6)2 (arene = benzene (2a), o-xylene (2b), mesitylene (2c), durene (2d), hexamethylbenzene (2e), and [2.2]paracyclophane (2g)) were obtained by iodide abstraction from [(σ5-indenyl)RhI2]n (1) with AgSbF6 in the presence of benzene and its derivatives. The procedure is also suitable for the synthesis of the dirhodium arene complex [(μ-σ:σ′-1,3-dimesitylpropane){Rh(σ5-indenyl)}2](SbF6)4 (3) starting from 1,3-dimesitylpropane. The structures of [2e](SbF6)2, [2g](SbF6)2, and [3](SbF6)4 were determined by X-ray diffraction. The last species has a sterically unfavorable conformation, in which the bridgehead carbon atoms of the indenyl ligand are arranged close to the propane linker between two mesitylene moieties. Experimental and DFT calculation data revealed that the benzene ligand in 2a is more labile than that in the related cyclopentadienyl complexes [(C5R5)Rh(C6H6)]2+. Complex 2c effectively catalyzes the reductive amination reaction between aldehydes and primary (or secondary) amines in the presence of carbon monoxide, giving the corresponding secondary and tertiary amines in very high yields (80-99%). This protocol is the most active in water. © 2018 American Chemical Society

Indenyl rhodium complexes. Synthesis and catalytic activity in reductive amination using carbon monoxide as a reducing agent

Indenyl-ligated rhodium(III) catalyst [(η5-indenyl)RhX2]n (1) is reported for the synthesis of alkylated amines via catalytic reductive amination using carbon monoxide as a reducing agent. Water as a solvent was found to be the best media for the reaction. Complex 1 was synthesized via a high-yielding procedure based on the reaction of bis(ethylene) derivative (η5-indenyl)Rh(C2H4)2 with iodine. © 2017 Elsevier B.V

Indenyl Rhodium Complexes with Arene Ligands: Synthesis and Application for Reductive Amination

An efficient protocol for synthesis of indenyl rhodium complexes with arene ligands has been developed. The hexafluoroantimonate salts [(σ5-indenyl)Rh(arene)](SbF6)2 (arene = benzene (2a), o-xylene (2b), mesitylene (2c), durene (2d), hexamethylbenzene (2e), and [2.2]paracyclophane (2g)) were obtained by iodide abstraction from [(σ5-indenyl)RhI2]n (1) with AgSbF6 in the presence of benzene and its derivatives. The procedure is also suitable for the synthesis of the dirhodium arene complex [(μ-σ:σ′-1,3-dimesitylpropane){Rh(σ5-indenyl)}2](SbF6)4 (3) starting from 1,3-dimesitylpropane. The structures of [2e](SbF6)2, [2g](SbF6)2, and [3](SbF6)4 were determined by X-ray diffraction. The last species has a sterically unfavorable conformation, in which the bridgehead carbon atoms of the indenyl ligand are arranged close to the propane linker between two mesitylene moieties. Experimental and DFT calculation data revealed that the benzene ligand in 2a is more labile than that in the related cyclopentadienyl complexes [(C5R5)Rh(C6H6)]2+. Complex 2c effectively catalyzes the reductive amination reaction between aldehydes and primary (or secondary) amines in the presence of carbon monoxide, giving the corresponding secondary and tertiary amines in very high yields (80-99%). This protocol is the most active in water. © 2018 American Chemical Society

Indenyl rhodium complexes. Synthesis and catalytic activity in reductive amination using carbon monoxide as a reducing agent

Indenyl-ligated rhodium(III) catalyst [(η5-indenyl)RhX2]n (1) is reported for the synthesis of alkylated amines via catalytic reductive amination using carbon monoxide as a reducing agent. Water as a solvent was found to be the best media for the reaction. Complex 1 was synthesized via a high-yielding procedure based on the reaction of bis(ethylene) derivative (η5-indenyl)Rh(C2H4)2 with iodine. © 2017 Elsevier B.V

Effect of Cp-Ligand Methylation on Rhodium(III)-Catalyzed Annulations of Aromatic Carboxylic Acids with Alkynes: Synthesis of Isocoumarins and PAHs for Organic Light-Emitting Devices

An efficient protocol was developed for the synthesis of π-extended isocoumarins and polycyclic aromatic hydrocarbons based on the oxidative coupling of aromatic carboxylic acids with internal alkynes catalyzed by (cyclopentadienyl)rhodium complexes. The coupling chemoselectivity strongly depends on whether Cp or the methylated Cp* ligands are used. The pentamethyl derivative [Cp*RhCl2]2 predominantly gives isocoumarins, while the non-methylated complex [CpRhI2]n produces naphthalene derivatives. The polyaromatic carboxylic acids (such as 1-naphthoic acid, 1-pyrenecarboxylic acid, fluorene-1-carboxylic acid, and dibenzofuran-4-carboxylic acid) are suitable for this approach. A mixture of Cp*H/RhCl3 can be used as a catalyst instead of [Cp*RhCl2]2. The structures of 3,4-diphenylindeno[1,2-h]isochromen-1(11H)-one and 7,10-dimethyl-8,9-diphenylbenzo[pqr]tetraphene were determined by X-ray diffraction. In addition, the optical properties of the prepared compounds were studied. 7,8-Diphenyl-10H-phenaleno[1,9-gh]isochromen-10-one was employed as an emissive layer for OLED manufacturing. The OLED emits yellow-green light with a maximum intensity 1740 cd ⋅ m−2 at 15 V. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei