Novel η1-allyl– and acyliridium(III)/pybox complexes

Abstract

The complex [IrCl( η 1-CH 2CH CH 2)( η 2-MeO 2CC CCO 2Me){ κ 3- N, N, N-( S, S)- i Pr-pybox}][PF 6] ( 1) has been prepared by oxidative addition of allyl chloride to a solution of the complex [Ir( η 2-MeO 2CC CCO 2Me) 2{ κ 3- N, N, N-( S, S)- i Pr-pybox}][PF 6] in acetone. The treatment of the complexes [Ir( η 2-C 2H 4) 2( κ 3- N,N,N-R-pybox)][PF 6] (R-pybox = 2,6-bis[4′-( S)-isopropyloxazolin-2′-yl]pyridine, 2,6-bis[4′-( R)-phenyloxazolin-2′-yl]pyridine) with ( E)-3-chloro-1-phenyl-1-propene (cinnamyl chloride) (1:1 molar ratio) in methanol at −40 °C, followed by warming to room temperature, affords stereoselectively the complexes [IrCl( η 1-CH 2CH CHPh)( η 2-C 2H 4)( κ 3- N, N, N-R-pybox)][PF 6] (R = ( S,S)- i Pr ( 2), ( R, R)-Ph ( 3)). Warming of acetonitrile solutions of complexes 2 or [IrCl( η 3-C 3H 5){ κ 3- N, N, N-( S, S)- i Pr-pybox}][PF 6] gives the complexes [IrCl( η 1-CH 2CH CHPh)(MeCN){ κ 3- N, N, N-( S, S)- i Pr-pybox}][PF 6] ( 4) and [IrCl( η 1-CH 2CH CH 2)(MeCN){ κ 3- N, N, N-( S, S)- i Pr-pybox}][PF 6] ( 5). Complex [Ir( η 2-C 2H 4) 2{ κ 3- N, N, N-( S, S)- i Pr-pybox}][PF 6] undergoes the oxidative addition of RCOCl (R = Me, Ph) in acetonitrile leading stereoselectively to the complexes [IrCl(COR)(MeCN){ κ 3- N, N, N-( S, S)- i Pr-pybox}][PF 6] (R = Me ( 6), Ph ( 7)). The structure of the complex 7 · CH 2Cl 2 has been determined by an X-ray monocrystal study.