Access to chiral β-amino sulfones from acrylamides and sulfur dioxide by iron catalysis†

A novel approach for the enantioselective synthesis of chiral β-azide sulfones utilizing sulfur dioxide (SO₂) insertion under the catalysis of a cheap, abundant and readily available iron catalyst has been successfully developed for the first time. This four-component reaction could be performed under mild conditions and has a broad substrate scope, giving products with a chiral quaternary carbon center. The obtained compounds can be easily converted into chiral β-amino sulfones which have considerable application values in the pharmaceutical and agrochemical industries. Mechanism study suggests that a radical pathway may be involved in the transformation.