Zhong Minling, Zhang Jie, Lu Zhenpin, Xie Zuowei
Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, China.
Dalton Trans. 2021 Nov 30;50(46):17150-17155. doi: 10.1039/d1dt03665c.
Small ring compounds are fascinating molecules and have been used as valuable compounds in organic synthesis. In this study, a carborane-fused four-membered boracycle bearing an electron precise B-B bond, 1,2-[BBrSMe]--CBH, was synthesized the reaction of 1,2-Li--carborane with BBr(SMe). This novel boracycle can be used as a "strain-release" compound to achieve diboration of alkenes and alkynes, leading to the generation of ring-expansion products. Interestingly, when bis(trimethylsilyl) acetylene was employed, an allene-functionalized six-membered boracycle was obtained. Moreover, DFT calculations were conducted to shed light on the reaction mechanism.
小环化合物是引人入胜的分子，并且已在有机合成中用作有价值的化合物。在本研究中，通过1,2-Li-碳硼烷与BBr（SMe）的反应合成了一种带有精确电子B-B键的碳硼烷稠合四元硼环，即1,2-[BBrSMe]--CBH。这种新型硼环可以用作“应变释放”化合物来实现烯烃和炔烃的双硼化，从而导致扩环产物的生成。有趣的是，当使用双（三甲基硅基）乙炔时，得到了一种烯丙基官能化的六元硼环。此外，还进行了密度泛函理论（DFT）计算以阐明反应机理。
