Condensation-Driven Assembly of Boron-Containing Bis(Heteroaryl) Motifs Using a Linchpin Approach

Herein, we describe
the bromomethyl acyl boronate linchpin–an
enabling reagent for the condensation-driven assembly of novel bis­(heteroaryl)
motifs. This building block is readily accessible from commercially
available starting materials. A variety of 2-amino- and 2-methylpyridines
were reacted with MIDA-protected bromomethyl acylboronate to afford
2-boryl imidazo­[1,2-a]­pyridine and 2-boryl
indolizine derivatives, respectively, in excellent yields. Subsequent
condensation with hydroxyamidines and hydrazonamides converted the
intermediate heterocycles into novel boron-containing bis­(heteroaryl)
units characterized by high thermal stability.

本文报道了溴甲基酰基硼酸酯锚定连接基——一种可用于缩合驱动组装新型双（杂芳基）骨架的赋能型试剂。该结构砌块可由市售起始原料便捷制备。将多种2-氨基吡啶与2-甲基吡啶分别与MIDA（N-甲基亚氨基二乙酸，N-Methyliminodiacetic acid）保护的溴甲基酰基硼酸酯进行反应，可分别以优异收率得到2-硼基咪唑并[1,2-a]吡啶与2-硼基中氮茚类衍生物。后续通过与羟脒类及腙酰胺类化合物发生缩合反应，可将该中间体杂环转化为具有高热稳定性的新型含硼双（杂芳基）单元。