Difluoro-λ<sup>3</sup>-Bromane-Induced Oxidative Carbon−Carbon Bond-Forming Reactions: Ethanol as an Electrophilic Partner and Alkynes as Nucleophiles
作者:Masahito Ochiai、Akira Yoshimura、Takeshi Mori、Yoshio Nishi、Masaya Hirobe
DOI:10.1021/ja801097c
日期:2008.3.1
Reported here for the first time are the oxidative couplings of alkynes and primary alcohols yielding conjugated enones. Although the BF3-catalyzed reaction of terminal alkynes with p-trifluoromethylphenyl(difluoro)-lambda3-bromane results in the fluoro-lambda3-bromanation of triple bonds to afford (E)-beta-fluorovinyl-lambda3-bromanes, reaction of an alkyne with the difluoro-lambda3-bromane in the
这里首次报道了炔烃和伯醇的氧化偶联产生共轭烯酮。尽管末端炔烃与对三氟甲基苯基(二氟)-λ3-溴烷的 BF3 催化反应导致三键的氟-λ3-溴化以提供 (E)-β-氟乙烯基-λ3-溴烷,但炔烃与在醇和 BF3-Et2O 存在下,二氟-λ3-溴以良好的产率提供直接共轭的烯酮。该反应在无金属条件下以高度立体选择性和区域选择性的方式进行。有趣的是,当使用二氟-λ3-碘烷 p-CF3C6H4IF2 代替 λ3-溴烷时,没有检测到烯酮的形成。一种涉及 lambda3-溴烷诱导的醇氧化为醛的机制,