The C–C bond reduction and metathesis are fundamentally important in organic synthesis. However, homogeneously reducible C–C bonds are currently limited to either strained rings or to specific and prefunctionalized sites; and there are no practical methods for tandem C–C reduction and intramolecular C(sp3)–C(sp3) metathesis. Here we report a versatile approach for selective reduction of unstrained C(sp3)–C(sp3) bond of ketones, including hydrogenolytic retro-[2+2+2]-cycloreversion of 2,4-diaroylcyclohexanols, without requiring protecting groups. We have also established an unprecedented intramolecular C(sp3)–C(sp3) metathesis, thus enabling the cyclizative degradation of poly(vinylketone). The present C–C cleavage occurs via a bimetallic pathway and nucleophile trapping of resulting enone is crucial for C–C cleavage relay. These results would open new prospect for deconstruction of organic molecules.
