Enantioselective Synthesis of vic-Aminoalcohol Derivatives by Nickel-Catalyzed Reductive Coupling of Aldehydes with Protected Amino-pentadienoates

A VAPOL-derived phosphoramidite ligand is uniquely effective at reverting the regiochemical course of nickel-catalyzed reactions of aldehydes with carbamate-protected 5-amino-2,4-pentadienoates as “push/pull” dienes; the ensuing carbonyl α-amino-homoallylation reaction affords anti-configured vic-aminoalcohol derivatives in good yields with high optical purity. The reductive coupling is conveniently performed with a bench-stable Ni(0) precatalyst and Et3B as the promoter.