Synthesis of γ‐Haloesters and γ‐Ketoesters by Homolytic Addition of Carbon Radicals Generated by α‐Haloesters and Triethylborane to Alkenes and Silyl Enol Ethers.

Abstract An efficient synthesis of γ-haloesters has been achieved, under very mild conditions, by addition of electrophilic carbon radicals ·CH(R)CO2Et (R=H, Me, CO2Et) generated by XCH(R)CO2Et (X=Br, I) / BEt3 / air in DMSO to alkenes and cycloalkenes. The synthesis of γ-ketoesters is also possible when silyl enol ethers are used as the substrates.