Controlled Hydrosilylation of Carbonyls and Imines Catalyzed by a Cationic Aluminum Alkyl Complex

The synthesis, characterization, and unprecedented catalytic activity of cationic aluminum alkyl complexes toward hydrosilylation are described. X-ray crystallographic analysis of Tp*AlMe2 (1) and [Tp*AlMe][I3] (3) revealed the preference of Al for a tetrahedral coordination environment and the versatility of the Tp* ligand in stabilizing Al in bi- and tridentate coordination modes. [Tp*AlMe][MeB(C6F5)3] (2) is highly active toward the hydrosilylation of a wide variety of carbonyls and imines, thus providing an inexpensive and versatile alternative to late transition metal catalysts.