Taw Felicia L, White Peter S, Bergman Robert G, Brookhart Maurice
Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
J Am Chem Soc. 2002 Apr 24;124(16):4192-3. doi: 10.1021/ja0255094.
Addition of 1.0 equiv of Ph3SiH to [Cp*(PMe3)Rh(Me)(CH2Cl2)]+BAr'4- (1) resulted in release of methane and quantitative formation of [Cp*(PMe3)Rh(SiPh3)(CH2Cl2)]+BAr'4- (2). Subsequent addition of 1.0 equiv of MeCN to 2 caused immediate displacement of dichloromethane to form the eta1-nitrile adduct [Cp*(PMe3)Rh(SiPh3)(NCMe)]+BAr'4- (3). Upon standing at room-temperature overnight, complex 3 converted quantitatively to another product which has been characterized as the C-C activation product, [Cp*(PMe3)Rh(Me)(CNSiPh3)]+BAr'4- (5). Addition of other nitrile substrates (R-CN, R = Ph, (4-CF3)Ph, (4-MeO)Ph, iPr, tBu) to 2 also resulted in C-C activation of the R-CN bond to form [Cp*(PMe3)Rh(R)(CNSiPh3)]+BAr'4-. Evidence for an eta2-iminoacyl intermediate complex, [Cp*(PMe3)Rh(eta2-C(R)=N(SiPh3)]+BAr'4-, is also presented.
向[Cp*(PMe3)Rh(Me)(CH2Cl2)]+BAr'4- (1)中加入1.0当量的Ph3SiH会导致甲烷释放，并定量生成[Cp*(PMe3)Rh(SiPh3)(CH2Cl2)]+BAr'4- (2)。随后向2中加入1.0当量的MeCN会立即导致二氯甲烷被取代，形成η1-腈加合物[Cp*(PMe3)Rh(SiPh3)(NCMe)]+BAr'4- (3)。在室温下放置过夜后，配合物3定量转化为另一种产物，该产物已被表征为C-C活化产物[Cp*(PMe3)Rh(Me)(CNSiPh3)]+BAr'4- (5)。向2中加入其他腈底物（R-CN，R = Ph、(4-CF3)Ph、(4-MeO)Ph、iPr、tBu）也会导致R-CN键发生C-C活化，形成[Cp*(PMe3)Rh(R)(CNSiPh3)]+BAr'4-。还给出了η2-亚氨基酰基中间体配合物[Cp*(PMe3)Rh(η2-C(R)=N(SiPh3)]+BAr'4-的证据。
