Preparation, identification and application of 1,3-bis triphenylphosphonium propane diborohydride in reduction of carbonyl compounds

Reduction is one of the most fundamental and useful reactions in organic synthesis.1 Sodium borohydride and lithium aluminum hydride are nucleophilic reducing agents which reduce polar multiple bonds.2 In order to control the reducing power of the reagents, hundreds of substituted boron and aluminum hydrides have been described in chemical literature and many are now commercially available.3Herein, 1,3- bis triphenylphosphonium propane diborohydride as a new, stable quaternary phosphonium borohydride is introduced and characterized by IR, NMR spectroscopy. This reagent is quantitatively prepared and used for reduction of variety of carbonyl compounds such as aldehydes, ketones, α, β-unsaturated carbonyl compounds and benzoil chlorides to their corresponding alcohols. Reduction reactions are performed in dry acetonitrile at room temperature or under solvent free conditions in good to excellent yields. In addition, this new reducing reagent indicates the chemoselective reduction of aldehydes over ketones

Keywords:

diphosphonium diborohydride , reducing agent , reduction reaction , carbonyl compounds.