Ligand-Controlled Chemoselective and Enantioselective Cyclization of Enynes With Aroyl Chlorides.

Herein, we report a palladium-catalyzed, ligand-controlled approach for the switchable construction of cyclopropane-fused heterocycles and seven-membered N-heterocyclic compounds via the chemoselective cyclization of enynes with aroyl chlorides. Furthermore, enantioselective synthesis of cyclopropane-fused heterocycles was achieved using a chiral ligand. To highlight the synthetic utility, late-stage modifications of acid chlorides derived from natural products and pharmaceuticals were demonstrated. DFT calculations reveal that the ligands play an important role in the chemoselective cyclization process by favoring either β-H or β-C elimination of the alkyl-Pd(II) intermediate.