Stabilization of Radicals by Imides. A Modular Stereoselective Approach to Protected Functional 1,2-Diamines

Radical addition of various xanthates to N,N'-diacylimidazol-2-one occurs readily to give protected 1,2-diamines. The imide group stabilizes the adduct radical sufficiently to enable a second addition to unactivated alkenes. In some cases, the addition product could be converted into an indoline, a tetralone, or further added to an indole. Regioselective removal of one acyl group could also be accomplished.