Diastereo- and Enantioselective (3 + 2) Cycloaddition of a New Aza-π-Allylpalladium Zwitterionic Intermediate.

Cycloaddition of azaoxyallyl cations or other C─(C═O)─N synthon precursors is a well-established route toward lactams and other N -heterocycles, but despite the wide synthetic scope of this approach, enantioselective versions remain scarce. We herein report 5-vinyloxazolidine-2,4-diones (VOxD) as a suitable precursor of a new palladium-π-allylpalladium intermediate. In the presence of electrophilic alkenes, (3 + 2) γ-lactam cycloadducts could be formed with a high level of diastereo- and enantioselectivity.