Fe-catalyzed highly selective ring expansion of alkynylcyclopropyl alkanols to cyclobutanols

摘要

A Fe-catalytic highly selective ring expansion reaction of alkynylcyclopropyl alkanols to alkynylcyclobutanols via a 1,2-carbon shift under mild conditions was developed. A new class of homogeneous FeCl_2/O_2 catalytic system was employed in these novel transformations. Transition metal-promoted ring expansion reactions of three-membered carbocycles activated by additional functional groups, such as cyclopropenes, methylenecyclopropanes (MCP) and vinylcyclopropanes (VCP), have been widely used in organic synthesis.