Pd-Catalyzed Domino Imidoylation/Heck/C(sp2)-H Cyclization: Isocyanide Relay Strategy toward Tricyclic-Fused Heterocycles Containing an All-Carbon Quaternary Center.

A palladium-catalyzed domino process for the quick assembly of tricyclic-fused heterocycles starting from aryl iodides and functionalized isocyanides containing a disubstituted terminal alkene has been developed. The process is triggered by intermolecular isocyanide insertion, followed by Heck-type carbopalladation of the intramolecular alkene moiety and subsequent C(sp2)-H activation. Moreover, an asymmetric version of this reaction could also be realized in good yield with moderate enantioselectivity after preliminary exploration of chiral ligands.