Monobromoborane-Dimethyl Sulfide-a Highly Promising Reagent for the Regio- and Chemoselective Brominative Cleavage of Terminal Epoxides into Vicinal Bromohydrins

摘要

Monobromoborane-dimethyl sulfide (BH2Br-SMe2) is a highly regio- and chemoselective reagent useful for the brominative cleavage of the epoxy moiety into bromohydrins in the presence of alkenes,alkynes,ethers,acetals,ketals,and acetonides at 0°C,besides being an excellent hydroborating reagent.Several reactive functional groups,such as chloride,ketones,esters,nitriles,nitros,and thioethers,have been accommodated during such transformations.Although the reduction of acetophenone was completely suppressed at -25°C,4-chlorobenzaldehyde still underwent 12-13% reduction of an aldehydic group.