Synthesis of indolizines via Pd-catalyzed selective ring recasting of oxazolidines with deesterification of methyl acrylates

The construction of nitrogen-containing heterocycles, which are important drug skeletons, by direct ring editing of readily available cyclic compounds, is well developed due to its high atom and step economy. Here, we report a practical and highly efficient strategy for the synthesis of a novel indolizine scaffold from N-propargyl oxazolidines and methyl acrylates. This reaction proceeds smoothly through a sequential process involving palladium-catalyzed cyclization, [3+2] cycloaddition, cycloreversion, oxidative deesterification, and aromatization. This approach facilitates the construction of a huge number of biologically active indolizines in moderate to good yields with high chemo- and regioselectivity. © 2025 Elsevier B.V.