Pyrrolidine-camphor derivative as an organocatalyst for asymmetic michael additions of α,α-disubstituted aldehydes to β-nitroalkenes: Construction of quaternary carbon-bearing aldehydes under solvent-free conditions

A novel pyrrolidine-camphor organocatalyst 3 was designed, synthesized and proven to be an efficient catalyst for the asymmetric Michael reaction. Treatment of α,α-disubstituted aldehydes with β-nitroalkenes in the presence of 20 mol% organocatalyst 3 and 20 mol% benzoic acid under solvent-free conditions provided the desired Michael product possessing an all-carbon quaternary center with high chemical yields (up to 99% yield) and high levels of enantioselectivities (up to 95% ee).