Synthesis of Amides from Acylboron Compounds

Abstract

Recently, acylboronates have been shown to be applicable in the fast and chemoselective synthesis of amides. The methods covered in this section include the use of potassium acyltrifluoroborates (KATs), N-methyliminodiacetyl (MIDA) acylboronates, and monofluoro(acyl)boronates. Acylboronates are, in general, bench-stable solids that can be easily handled in the laboratory. Among them, potassium acyltrifluoroborates stand out as remarkably stable salts that resist a variety of reaction conditions including acid, base, and heating. N-Methyliminodiacetyl acylboronates have the advantage of being amenable to purification by column chromatography and they exhibit high reactivity in amide ligation, but are limited by their poor stability under aqueous conditions. Monofluoro(acyl)boronates lie in between the above two classes, having acceptable half-life values in solution and improved overall reactivities compared to potassium acyltrifluoroborate reagents.