Olefination of N-Sulfinylimines under Mild Conditions

A very simple and efficient diastereoselective synthesis of 1,2-disubstituted alkenes has been achieved under mild conditions. Sulfoxide stabilised N-sulfinylimines reacted with in-situ-generated phosphonate carbanions to give 1,2-disubtituted alkenes in good to excellent yields. Different aryl phosphonates reacted with a range of electronically diverse N-sulfinylimines to give alkenes with >99:1 E selectivity. The most important feature of this protocol is that the reaction can be carried out at room temperature with inexpensive sodium hydride as the most effective base to generate the reactive phosphonate carbanions, and producing the alkenes with E selectivity in up to 85 % isolated yield.