Divergent rhodium-catalyzed electrochemical vinylic C–H annulation of acrylamides with alkynes

Abstract α-Pyridones and α-pyrones are ubiquitous structural motifs found in natural products biologically active small molecules. Here, we report an Rh-catalyzed electrochemical vinylic C–H annulation of acrylamides with alkynes, affording cyclic good to excellent yield. Divergent syntheses α-pyridones imidates accomplished by employing N- phenyl tosyl as substrates, respectively. Additionally, regioselectivities achieved when using unsymmetrical alkynes. This process is environmentally benign compared traditional transition metal-catalyzed annulations because it avoids the use stoichiometric metal oxidants. DFT calculations elucidated reaction mechanism origins substituent-controlled chemoselectivity. The sequential activation alkyne insertion under rhodium catalysis leads seven-membered ring vinyl-rhodium intermediate. intermediate undergoes either classic neutral concerted reductive elimination produce α-pyridones, or ionic stepwise pathway imidates.