Radical Addition to 2-Allenylaryl Isocyanides for the Preparation of 2,3-Difunctionalized Quinolines.

2-Allenylaryl isocyanides are presented as a novel platform to construct quinolines carrying various substituents in positions 2 and 3 via radical addition cyclization cascades. Carbon-, sulfur-, and tin-centered radicals add to the isonitrile functionality to generate the corresponding imidoyl radicals, which undergo 6-exo-cyclization onto the ortho-allenyl moiety. The newly generated benzylic radicals are either reduced or cyanated. In the latter case, enantioselective trapping is achieved.