Copper-Mediated Divergent Reactivity of Allene-Tethered Carbamates under Radical Conditions.

By judicious selection of reaction conditions, the controllable copper-promoted bromoheterocyclization or the sulfonylation/dimerization of allenyl carbamates to access 5-bromo-6-methylene-1,3-oxazinan-2-ones or bis(γ-amino vinyl sulfones) has been implemented. The described method, which is easy to scale up and exhibits good functional group tolerance, displays exquisite selectivity control for the preparation of two structurally different compounds starting from the same precursors under free radical conditions.