Hemilabile Pincer-Type Hydride Complexes of Iridium
摘要:
The ligand (Bu2PC2H4NHC2H4NEt2)-Bu-t (PNHN) was synthesized starting from 2-(diethylamino)ethyl chloride hydrochloride and ethanolamine. Reaction of PNHN with [IrCl(COE)(2)](2) under H-2 afforded the dihydride cis-IrH2Cl(kappa(3)-PNHN) (1) in excellent yield. Treatment of 1 with (BuOK)-Bu-t led to clean formation of the 16-electron amido complex IrH2(kappa(3)-PNN) (2). Hydrogenation of 2 in toluene or ethyl acetate produced the trihydride mer-IrH3(kappa(3)-PNHN) (3). This complex was unstable and dimerized to give [IrH2(kappa(2)-PNHN)](2)(mu-H)(2) (4) with uncoordinated NEt2 groups. The structures of 1 and 4 were established by X-ray crystallography. Complex 2 demonstrated good catalytic activity for transfer hydrogenation of acetophenone, cyclohexanone, and butanone.
Hemilabile Pincer-Type Hydride Complexes of Iridium
作者:Aldjia Choualeb、Alan J. Lough、Dmitry G. Gusev
DOI:10.1021/om700550x
日期:2007.10.1
The ligand (Bu2PC2H4NHC2H4NEt2)-Bu-t (PNHN) was synthesized starting from 2-(diethylamino)ethyl chloride hydrochloride and ethanolamine. Reaction of PNHN with [IrCl(COE)(2)](2) under H-2 afforded the dihydride cis-IrH2Cl(kappa(3)-PNHN) (1) in excellent yield. Treatment of 1 with (BuOK)-Bu-t led to clean formation of the 16-electron amido complex IrH2(kappa(3)-PNN) (2). Hydrogenation of 2 in toluene or ethyl acetate produced the trihydride mer-IrH3(kappa(3)-PNHN) (3). This complex was unstable and dimerized to give [IrH2(kappa(2)-PNHN)](2)(mu-H)(2) (4) with uncoordinated NEt2 groups. The structures of 1 and 4 were established by X-ray crystallography. Complex 2 demonstrated good catalytic activity for transfer hydrogenation of acetophenone, cyclohexanone, and butanone.