Asymmetric Ni Phosphite Catalyzed Trialkylaluminum Addition to Aldehydes

Significance

Novel methods of catalytic asymmetric C-C bond formation are among the most actively studied areas of enantioselective catalysis. The asymmetric addition of trialkylaluminum compounds is of special interest, as they are available in industrial scale from olefins and aluminum hydride. This is one of the first reports of a really practical method for the addition of AlR₃ (R = Alk) to aldehydes, using relatively low amounts of a phosphorus catalyst. The chiral phosphite, used as a ligand, is available in three steps from d-glucose. Very high enantioselectivities were achieved with only 1 mol% of the resulting Ni catalyst. A safe and air-stable complex of DABCO with AlMe₃ (DABAL-Me₃) was used for the introduction of a methyl group.