One-Pot Synthesis of 2,5-Dihydrosiloles and Their Silole-Annulated Analogs Starting from Alkynylsilanes with a Terminal Alkynyl Group
作者:Oleg L. Tok、Jonathan Bould、Michal Dušek、Josef Cvačka
DOI:10.1021/acs.joc.0c02711
日期:2021.3.5
In contrast to the reaction of vinyl(alkynyl)silanes with 9-BBN-H, leading to the quantitative formation of 5-R-4-(9-BBN)-2,3-dihydro-1H-siloles, treatment of bis(alkynyl)silanes bearing one terminal alkynyl group with 2 equiv of 9-BBN-H followed by methanolysis afforded 5-R-4-(9-BBN)-2,5-dihydro-1H-siloles with yields of 85–90% (by NMR integration). The reaction proceeds via a double 1,2-hydroboration
与乙烯基(炔基)硅烷与9-BBN-H的反应相反,导致定量形成5-R-4-(9-BBN)-2,3-二氢-1 H-硅酮,双酚的处理带有一个末端炔基和2个当量的9-BBN-H的(炔基)硅烷,然后进行甲醇水解,制得5-R-4-(9-BBN)-2,5-二氢-1 H-硅酮,产率为85–90 %(通过NMR积分)。反应通过末端三键的双1,2-氢硼化与双乙硼烷的形成而进行,然后通过剩余炔基片段的分子内1,1-碳硼化进行闭环。取决于位置5上取代基R的性质,烯丙基BBN基团位于位置3(R = Ph)或位置5(R = SiHMe 2,SiMe 3)分别得到2,3-或2,5-二氢甲硅烷基。用3,4-(9-BBN)2 -2,3-二氢-和4,5-(9-BBN)2 -2,5-二氢-甲硅烷的MeOH对烯丙基BBN基团进行原基去硼化反应4-(9-BBN)-2,5-二氢硅酮。在所有情况下,都观察到形成了10–12%的2-R-2