Preparation of 1,2-Oxazetidines from Styrenes and Arylamines via a Peroxide-Mediated [2 + 1 + 1] Cycloaddition Reaction.

The first regioselective synthesis of polysubstituted 1,2-oxazetidines, based on the [2 + 1 + 1] radical tandem cycloaddition of styrenes, arylamines, and tert-butyl hydroperoxide (TBHP), is described. This simple and direct method allows the synthesis of 1,2-oxazetidines with a broad substrate scope from easily accessible materials. TBHP was employed in this conversion not only as the oxidant but also as the source of "O" for the carbonyl group in the products.