Copper-catalyzed enantioselective diyne cyclization C(sp)-O bond cleavage.

The functionalization of etheric C-O bonds 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(sp)-O bond cleavage, and a catalyst-controlled highly enantioselective version is extremely challenging. Here, we report a copper-catalyzed asymmetric cascade cyclization C(sp)-O bond cleavage, allowing the divergent and atom-economic synthesis of a range of chromeno[3,4-]pyrroles bearing a triaryl oxa-quaternary carbon stereocenter in high yields and enantioselectivities.