Regioselective Pd-Catalyzed Carbopalladation/Decarboxylative Allylic Alkynylation of ortho-Iodoallenamides with Alkynyl Carboxylic Acids

A regioselective Pd-catalyzed domino carbopalladation/decarboxylative allylic alkynylation of ortho-iodoallenamides with alkynyl carboxylic acids was studied. This domino process, based on the consecutive formation of C(sp(2))-C(sp(2)) and C(sp(3))-C(sp) bonds, was originally achieved for the design of a novel library of prop-2-ynyl isoquinolinones and then extended to indoles. Finally, a general three-step one-pot strategy involving in situ generation of allenamide, pi-allyl-Pd complex formation, and decarboxylative allylic alkynylation was subsequently set up.