SILYL AND BIS(SILYL)HYDRIDE COMPLEXES OF RUTHENIUM - EFFECT OF ANCILLARY GROUPS ON THE OXIDATIVE ADDITION OF SI-H BONDS

Ruthenium alkyl complexes Cp(PMe(3))(2)RuCH(2)SiMe(3) (2) and Cp(PPh(3 ))(2)RuMe (3) reacted with hydrosilanes forming ruthenium silyl and/or bis(silyl)hydride complexes. Complex 2 reacted with HSiR(3) at 100 de grees C forming the corresponding silyl complexes Cp(PMe(3))(2)RuSiR(3 ) [SiR(3) = SiCl3 (4), SiMeCl(2) (5), SiMe(2)Cl (6)] in high yields. A t 125-150 degrees C, 2 reacted with HSiEt(3) giving a mixture of the s ilyl Cp(PMe(3))(2)RuSiEt(3) (7) and the bis(silyl)hydride Cp(PMe(3))Ru (SiEt(3))(2)H (8); this mixture can be converted solely to 7 upon reac tion with PMe(3). Complex 3 reacted with HSiEt(3) at 100 degrees C for ming Cp(PPh(3))(2)RuSiEt(3) (9). The reaction of 3 with neat HSiCl3 at 100 degrees C forms a mixture of Cp(PPh(3))Ru(SiCl3)(2)H (10) and Cp( PPh(3))(2)RuSiCl3 (11), with 10 being the major product. At lower conc entrations of HSiCl3 (<2 M), the reaction with 3 forms mixtures of 10 and 11 but with 11 being the major product. Mixtures of 10 and 11 can be converted to 11 upon reaction with excess PPh(3). Similarly, 11 rea cts with neat HSiCl3 to generate a mixture of 10 and 11. The effects o f the ancillary ligands on ruthenium and the nature of the hydrosilane on the rate and course of reaction are also discussed. Copyright (C) 1996 Elsevier Science Ltd