Design, synthesis, and application of multiboron heterocycle to direct amidation catalyst

The synthesis of a multiboron heterocycle and its application to a direct amidation catalyst are described. The heterocycle comprised of B₃NO₂is called DATB. The DATB-catalyzed direct amide formation is well suited for the synthesis of a wide range of amides, including previously intractable ones. The catalysis can also be applied to peptide synthesis and N-acylation of sulfoxi- mines. The most active DATB contains four boron atoms in its structure, and the detailed mecha- nistic study revealed their distinctive roles in the catalytic cycle, depending on the given chemical environment. A pyrimidine containing analog was also developed and evaluated as a more readily accessible amidation catalyst than the original one. The Pym-DATB is now available from a commercial vendor. Current trends and future perspective in the boron - catalyzed direct amidation are also discussed.