Trialkyl imido niobium and tantalum compounds: synthesis, structural study and migratory insertion reactions†‡
Abstract
Trialkyl imido niobium and tantalum complexes [MR3(NtBu)] (M = Nb, R = Me 2, CH2CMe33, CH2CMe2Ph 4, CH2SiMe35; M = Ta, R = Me 6, CH2CMe2Ph 7, CH2SiMe38) have been prepared by treatment of solutions containing [MCl3(NtBu)py2] (M = Nb 1a, Ta 1b) with three equivalents of magnesium reagent. By an unexpected hydrolysis reaction of the tris-trimethylsilylmethyl imido tantalum compound 8a, a μ-oxo derivative [(Me3SiCH2O)(Me3SiCH2)3Ta(μ-O)Ta(CH2SiMe3)2(NtBu)] (8a) was formed and its structure was studied by