Direct Conversion of Ethyl Ketone to Alkyl Ketone via Chelation-Assisted Rhodium(I)-Catalyzed Carbon–Carbon Bond Cleavage: Ligands Play an Important Role in the Inhibition of β-Hydrogen Elimination

Quinolinone derivatives were synthesized by exchanging the ethyl group of 1-(quinolin-8-yl)propan-1-one with substituted styrenes via group-directed carbon–carbon bond cleavage. A series of substituted styrenes were reacted with 1-(quinolin-8-yl)propan-1-one for the production of various substituted 3-phenyl-1-(quinolin-8-yl)propan-1-ones in medium and good yields. The catalytic system combining [Rh(COD)Cl]2 (5.0 mol %) with Et3N (2.5 equiv) and 1,3-bis(diphenylphosphino)propane (10 mol %) was optimal for these transformations.