Reaction of ruthenium complexes having both a phosphite and a group 14 element ligand with a Lewis acid

Reactions of Cp(CO)(ER3)Ru{PN(Me)CH2CH2NMe(OMe)} having an alkyl group (ER3 = Me (1a), CH2SiMe3 (2a)), a silyl group (ER3 = SnMe3 (3a), SiMe2SiMe3 (4a )), a germyl group (ER3 = GeMe3 (5a)), or a stannyl group (ER3 = SnMe3 (6a) , (SnBu3)-Bu-n (7a), SnPh3 (8a)) with a Lewis acid (BF3 OEt2 or Me3SiOSO2CF 3 (TMSOTf)) have been examined. In the reactions with BF3 . OEt2, in any ca se except for 8a, an OMe abstraction as an anion uniformly takes place at t he first stage to give the corresponding cationic phosphenium complex [Cp(C O)(ER3)Ru{PN(Me)CH2CH2NMe}]BF4 (1b-7b). The successive reaction depends on the type of ER3 group. Alkyl complexes (1b and 2b) immediately undergo migr atory insertion of the phosphenium ligand into the Ru-C bond, and a subsequ ent reaction with PPh3 gives the cationic complex [Cp(CO)(PPh3)Ru{PN(Me)CH2 CH2NMe(ER3)}]BF4 (ER3 = Me (1c), CH2SiMe3 (2c)). Silyl and germyl complexes (3b-5b) are stable with the Ru-Si and Ru-Ge bonds intact. In contrast, sta nnyl complexes (6b and 7b) undergo migration of one of the R groups on Sn t o give the stannylene complex [Cp(CO)(PN(Me)CH2CH2NMe(R))Ru=SnR2]BF4 (R = M e (6e), Bu-n (7e)). The reactions with another Lewis acid, TMSOTf, exhibit reactivities similar to those with BF3 . OEt2, except when ER3 is a stannyl group. In the reaction of 6a, 7a, or 8a with TMSOTf one of the R groups on Sn is directly abstracted to give the corresponding stannylene complex [Cp (CO){PN(Me)CH2CH2NMe(OMe)}Ru=SnR2]OTf(R = Me (6f), Bu-n (7f), Ph (8f)). 8f has been determined to be a doubly base stabilized stannylene complex by si ngle-crystal X-ray diffraction.