the bite angle of the diphosphineligand in the copper catalyst, and we identified an achiral diphosphineligand L1 bearing an exceptionally large bite angle as the optimal ligand. A copper(I)-conjugated Brϕnsted base catalyst containing ligand L1 enabled the C–C bond-forming reaction via in situ-generated copper(I) enolate, even in the presence of multiple unprotected hydroxy groups. A variety of ketones