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

A new protocol for the palladium‐catalyzed free‐amine‐directed alkenylation of C(sp2)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. Seven‐membered cycloamination: A new protocol for the palladium‐catalyzed free‐amine‐directed alkenylation of C(sp2)H bonds and subsequent cycloamination is described (see scheme). Substituted biaryl‐2‐amines react with various 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.