Metal-Free Reductive Cleavage of C-0 a-bonds in Acyloin Derivatives by an Organic Neutral Super-Electron-Donor

摘要

Neutral organic electron-donor 7, formally a pyridinylidene carbene dimer, effects reductive cleavageof C-O a-bonds in acyloin derivatives Ar(CO)CRR'OX (X = OAc, OPiv, OBz, OMs) and thisrepresents the first cleavage of C-0 a-bonds by a neutral organic electron-donor. The methodologyis applicable to a large array of substrates and the reduced counterparts were isolated in good toexcellent yields. For certain substrates, donor 7 behaves as a base, effecting condensation reactionswith some acetate ester derivatives of acyloins, leading to butenolides. The variation in reactivityamong the different substrates was rationalized.