RESUMEN
A wide range of 2-pyridyl and other difficult-to-access heterocyclic N-methyliminodiacetic acid boronates can be readily prepared from the corresponding bromides via a new method involving direct transligation of 2-heterocyclic trialkoxyborate salts with N-methyliminodiacetic acid (MIDA) at elevated temperatures.
Asunto(s)
Ácidos Borónicos/síntesis química , Compuestos Heterocíclicos/síntesis química , Iminoácidos/síntesis química , Ácidos Borónicos/química , Cristalografía por Rayos X , Compuestos Heterocíclicos/química , Iminoácidos/química , Modelos Moleculares , Estructura Molecular , EstereoisomerismoRESUMEN
Many boronic acids, including 2-heterocyclic, vinyl, and cyclopropyl derivatives, are inherently unstable, which can limit their benchtop storage and/or efficient cross-coupling. We herein report the first general solution to this problem: in situ slow release of unstable boronic acids from the corresponding air-stable MIDA boronates. This remarkably general approach has transformed all three classes of these unstable boronic acids into shelf-stable and highly effective building blocks for cross-coupling with a wide range of aryl and heteroaryl chlorides.
