A Unified Strategy Toward 5‐, 6‐, and 7‐Membered Nitrogen Heterocycles Through Free Radical then Metal‐Mediated Functionalization of Ene‐carbamates

Abstract. Free-radical carbo-alkenylation of N-aryl, N-benzyl, and N-phenethyl-ene-carbamates with a disulfone provides vinylsulfones which may then be functionalized and engaged in Heck-type coupling to furnish highly substituted 5-, 6- and 7-membered nitrogen heterocycles. Grignard-mediated cyclization starting from the same substrates further allowed a nucleophilic cascade process, affording a straightforward access to hydrocarbazoles, which may be regarded as potent intermediates for the synthesis of alkaloids of the aspidosperma family.