作者:Holger Braunschweig、Giovanni D'Andola、Tom Welton、Andrew J. P. White
DOI:10.1002/chem.200500760
日期:2006.1
A series of alpha,omega-boryl(bromo)alkanes of the general formula R2B-(CH2)n-Br (n = 3, 4, 5, 6) was obtained in high yield following a standard hydroboration protocol. Upon treatment with Mg turnings and formation of the respective Grignard species, all alkanes with n = 4 to 6 underwent an unprecedented boron-centered cyclisation reaction with formation of boratacyclopentanes, -hexanes, and -heptanes
按照标准的硼氢化方法,以高收率获得了一系列通式为R2B-(CH2)n-Br(n = 3、4、5、6)的α,ω-硼烷基(溴)烷烃。在用Mg车削处理并形成各自的格利雅(Grignard)物种后,所有n = 4至6的烷烃都经历了前所未有的以硼为中心的环化反应,并分别形成了硼烷基环戊烷,-己烷和-庚烷。以高收率分离出所有新化合物,为无色结晶物质,并通过多核NMR光谱法在溶液中表征。选择了四个代表性实例进行X射线衍射研究,从而在硼酸四烷基酯中心提供了该结构的第一个结构表征的环系统。