Diborane as a reducing agent—I : The reduction of electron-rich aromatic aldehydes and ketones

Abstract

Aromatic aldehydes and ketones bearing electron-releasing substituents are usually reduced to the corresponding substituted hydrocarbons by diborane generated by “externally” or in the reaction mixture. It is suggested that the greater potency of borontrifluoride-borohydride mixtures in effecting the “internal” reductions is due to the presence of both electrophilic and nucleophilic species in the reaction medium. Anisaldehyde gives complex mixtures on reduction by “internally” generated diborane.