Palladium Catalyzed C-H Olefination of Indolizines at the 1-Position with Molecular Oxygen as the Terminal Oxidant

A regioselective C1-olefination of indolizines enabled by Pd-II-catalyzed non-directed C-H activation has been developed. Molecular oxygen is employed in this protocol as the terminal oxidant and with a catalytic amount Cu-II salt as the co-oxidant. A broad range of simple and highly fused indolizine substrates were compatible with the reaction conditions, enabling the straightforward synthesis of valuable C1-substituted indolizine derivatives.