Enantioselective Synthesis\nof <i>vic</i>-Aminoalcohol Derivatives by Nickel-Catalyzed\nReductive Coupling\nof Aldehydes with Protected Amino-pentadienoates

A VAPOL-derived phosphoramidite ligand is uniquely effective\nat\nreverting the regiochemical course of nickel-catalyzed reactions of\naldehydes with carbamate-protected 5-amino-2,4-pentadienoates as “push/pull”\ndienes; the ensuing carbonyl α-amino-homoallylation reaction\naffords <i>anti</i>-configured <i>vic</i>-aminoalcohol\nderivatives in good yields with high optical purity. The reductive\ncoupling is conveniently performed with a bench-stable Ni(0) precatalyst\nand Et<sub>3</sub>B as the promoter.