Highly diastereoselective synthesis of borylcyclopropanes by copper-catalyzed borylcyclopropanation of alkenes with enynones

Abstract

The copper-catalyzed diastereoselective borylcyclopropanation of alkenes with α-furyl boryl copper carbenes generated from BMIDA-terminated enynones allows facile and practical synthesis of various borylcyclopropanes in moderate to excellent yields (up to 98%) with excellent diastereoselectivities (mostly d.r. > 25:1) under mild reaction conditions. Moreover, this protocol is applicable for the late-stage functionalization of complex bioactive molecules, which together with large-scale experiments and synthetic transformations of the products demonstrate the synthetic potential of this methodology.