Cyclopropanation/Carboboration Reactions of Enynes with B(C6F5)3

详细信息    查看全文

• 作者：Max M. Hansmann ; Rebecca L. Melen ; Matthias Rudolph ; Frank Rominger ; Hubert Wadepohl ; Douglas W. Stephan ; A. Stephen K. Hashmi
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：December 16, 2015
• 年：2015
• 卷：137
• 期：49
• 页码：15469-15477
• 全文大小：686K
• ISSN：1520-5126

文摘

Stoichiometric reaction of B(C₆F₅)₃ with 1,6-enynes is shown to proceed via initial cyclopropanation and formal 1,1-carboboration. Depending on the substitution on the alkene moiety, subsequent ring-opening of the cyclopropane affords either cyclopentane or cyclohexane derivatives in which the C₆F₅ and B(C₆F₅)₂ adopt a 1,4-positioning. Mechanistically, this transformation involves 蟺-activation of the alkyne moiety, which triggers cyclopropanation, followed by carboboration. Both the cyclopropanation and subsequent ring-opening are shown to be stereospecific. Both cyclopropanation and 1,4-carboborated products were employed as Lewis acid components in frustrated Lewis pair activation of H₂ and CO₂.