Cycloadditions of 5-Vinyloxazolidine-2,4-diones: A Straightfor-ward Access to the (thio)Hydantoin Scaffold

A palladium-catalyzed (3+2) cycloaddition between 5-vinyloxazolidine-2,4-diones (VOxD) and (thio)isocyanates is described. Under optimized conditions, an array of (thio)hydantoins was readily prepared and an enantioselective version of this transformation was then studied. To illustrate the importance of this method, a concise synthesis of two bioactive compounds, nirvanol and mephenytoin, was carried out. This work emphasizes the synthetic potential of VOxD as useful precursors of zwitterionic aza-π- allylpalladium II intermediates.