Bromo-Boronolactonization of Olefins¹

Abstract

Exposure of a variety of mono- and disubstituted ortho-alkenylarylboronic acids to NBS in THF/H(2)O under neutral conditions affords bromo-boronolactones, in some instances, with exceptional regiocontrol. The adducts, analogous to those formed by carboxylic acids, are shown to be useful synthetic intermediates.