Enantioselective Synthesis of β-Nitro Phosphonates Catalyzed by a Secondary Amine Bisthiourea

Abstract

An enantioselective Michael addition of diphenyl phosphonate to nitroalkenes has been developed by using a secondary amine bisthiourea catalyst to access enantiomerically enriched β-nitro phosphonates. In this reaction, molecular sieves play a key role in achieving high and reproducible yields with a high enantioselectivities of up to 99% at –10 °C. A probable mechanism for the enantioselective Michael addition reaction was established by means of an NMR spectroscopic study.