Unexpected Reduction of N-Hydroxyphthalimides to Phthalimides - OrthogonalReduction of Functionalized N-Hydroxyphthalimides

A chemoselective reduction of N-hydroxyphthalimides to phthalimides under mild conditions has been discovered. It involves reaction of an N-hydroxyimide with bis(pinacolato)diboron in the presence of a base. Other easily reducible functional groups, such as iodo, nitro, or azido groups are unaffected. Alternatively, such functional groups may be selectively reduced without affecting the N-hydroxyimide moiety using a set of classical conditions.