In situ Catalytic Generation of Allylcopper Species for Asymmetric Allylation: Toward 1H-Isochromene Skeletons


  • This work was supported by ERATO from JST (M.K.) and Grant-in-Aid for Research Activity Start-up from JSPS (Y.S.). We thank Dr. Hiroyasu Sato (Rigaku Corporation) for helpful suggestions about X-ray analysis.


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Stay active: Allylcopper species can be generated in situ through catalytic intramolecular oxycupration of allenic alcohol. The allylcopper can react with various aldehydes and a ketone to give 1H-isochromene derivatives in an enantioselective manner (see scheme; HMPA=hexamethylphosphoramide, THF=tetrahydrofuran). The protocol is atom-economical, highly regioselective, stereoconvergent, and tolerant to free hydroxy groups.