Hydrosilylation of phenylacetylene catalyzed by [Ir(COD)(η2-iPr2PCH2CH2OMe)][BF4]
作者:Miguel A. Esteruelas、Montserrat Oliván、Luis A. Oro、JoséI. Tolosa
DOI:10.1016/0022-328x(94)05110-w
日期:1995.2
In the presence of the complexes [Ir(diolefin)(eta(2)-(i)Pr(2)PCH(2)CH(2)NMe(2))][BF4] (diolefin = 1,5-cyclooctadiene (COD) (1) or tetrafluorobenzobarrelene (TFB) (2)) and [Ir(diolefin)(eta(2)-(Pr2PCH2CH)-Pr-i(2)OMe)][BF4] (diolefin = COD (3) or TFB (4)), phenylacetylene undergoes reaction with triethylsilane. In all experiments carried out PhCH=CH2, PhC=CSiEt(3), cis-PhCH=CH(SiEt(3)), trans-PhCH=CH(SiEt(3)) and Ph(SiEt(3))C=CH2 were obtained. An investigation in detail for the catalyst 3 suggests that, under catalytic conditions, the complexes [IrH(C(2)Ph)(COD)(eta(2)-(i)Pr(2)PCH(2)CH(2)OMe)]BF4 (5) and [IrH(SiEt(3))(COD)(eta(2)-(i)Pr(2)PCH(2)CH(2)OMe)]BF4 (6) are formed. Complex 5 is the key intermediate for the formation of PhC=CSiEt(3), while 6 is the species leading to cis-PhCH=CH(SiEt(3)). The isomer trans-PhCH=CH(SiEt(3)) is formed by isomerization of cis-PhCH=CH(SiEt(3)). The mechanisms of formation of these compounds are discussed.