Facile 1,2-Migration of a Methyl Group on a {Dimethoxy(methyl)silyl}tungsten Complex: Formation of a Base-Stabilized (Dimethoxysilylene)(methyl) Complex
摘要:
Reactions of Cp*(CO)(2)W(DMAP)Me[1, Cp* = eta(5)-C5Me5, DMAP = 4-(dimethylamino)pyridine] with trialkylsilanes HSiR2Et (R = Me, Et) afforded (DMAP)(trialkylsilyl)tungsten complexes Cp*(CO)(2)W(DMAP)(SiR2Et) (2a, R = Me; 2b, R = Et). On the other hand, a reaction of 1 with dimethoxy(methyl)silane, HSi(OMe)(2)Me, gave a DMAP-stabilized (dimethoxysilylene)tungsten complex, cis-Cp*(CO)(2)W(Me){=Si(OMe)(2). DMAP} (cis-3), through 1,2-migration of a methyl group from silicon to tungsten. Silylene complex cis-3 isomerized to its lions-isomer trans-3,