1,4-Bromoboration of Nitroalkenes

Abstract

The selective 1,4-bromoboration of nitroalkenes occurs under mild conditions with a bromoborane featuring two 1-methyl-ortho-carborane substituents, BrB^MeoCb₂. The bromide is introduced on the β-carbon and the boryl moiety on the nitro group is bound to boron in a κ² manner. Screening a variety of other haloboranes gave either no reaction or indiscernible mixtures indicating the necessity for the BrB^MeoCb₂ reagent. The haloboration reaction tolerates a variety of aryl functional groups as well as a hydrogen or methyl group on the α-carbon that all proceed with excellent regioselectivity and high isolated yields.