Free-Amine-Directed Alkenylation of C(sp2)[BOND]H and Cycloamination by Palladium Catalysis



A new protocol for the palladium-catalyzed free-amine-directed alkenylation of C(sp2)[BOND]H bonds and cycloamination is described. Substituted biaryl-2-amines react with various alkenes, including electron-deficient alkenes, aryl alkenes and alkyl alkenes, to give the corresponding phenanthridines with exclusive regioselectivity. The use of α-branched styrenes leads to the formation of tricyclic compounds with a seven-membered amine ring. The method operates through a free-amine-directed alkenylation and a subsequent hydroamination cyclization reaction.