Copper-catalyzed enantioselective diyne cyclization via C(sp2)–O bond cleavage

Abstract

The functionalization of etheric C–O bonds via C–O bond cleavage is an attractive strategy for the construction of C–C and C–X bonds in organic synthesis. However, these reactions mainly involve C(sp³)–O bond cleavage, and a catalyst-controlled highly enantioselective version is extremely challenging. Here, we report a copper-catalyzed asymmetric cascade cyclization via C(sp²)–O bond cleavage, allowing the divergent and atom-economic synthesis of a range of chromeno[3,4-c]pyrroles bearing a triaryl oxa-quaternary carbon stereocenter in high yields and enantioselectivities. Importantly, this protocol not only represents the first [1,2]-Stevens-type rearrangement via C(sp²)–O bond cleavage, but also constitutes the first example of [1,2]-aryl migration reactions via vinyl cations.