AbstractThe incorporation of two distinct boryl groups at the same carbon center in organic molecules has attracted growing research interest due to its potential for facilitating controlled, precise synthesis through stepwise dual carbon‐boron bond transformations. Here we report a method to access unsymmetrical 1,1‐diborylalkene (UDBA) stereoselectively via the reaction of readily available alkynes with a neutral sp2−sp3 diboron reagent (NHC)BH2‐Bpin (NHC=N‐heterocyclic carbene). Attributing to the chemically easily distinguishable nature of the sp2 and sp3 boryl moieties, controllable stepwise derivatization of the resultant UDBAs is realized. This process leads to various multifunctionalized olefins and organoborons, such as acylboranes, which are difficult to prepare by other methods.
摘要 在有机分子的同一碳中心加入两个不同的硼烷基,由于其通过逐步双碳硼键转化促进可控、精确合成的潜力,引起了越来越多的研究兴趣。在此,我们报告了一种通过现成的炔烃与中性 sp2-sp3 二硼试剂 (NHC)BH2-Bpin (NHC=N-heterocyclic carbene) 反应,立体选择性地获得非对称 1,1 二硼烯 (UDBA) 的方法。由于 sp2 和 sp3 硼烷基的化学性质很容易区分,因此可以对生成的 UDBA 进行可控的逐步衍生。通过这一过程,可制备出各种多功能烯烃和有机硼,如酰基硼烷,而这些烯烃和有机硼是很难用其他方法制备的。