Brønsted acid-catalysed hydroarylation of unactivated alkynes in a fluoroalcohol–hydrocarbon biphasic system: construction of phenanthrene frameworks
作者:Ikko Takahashi、Takeshi Fujita、Noriaki Shoji、Junji Ichikawa
DOI:10.1039/c9cc04152d
日期:——
Transition metal-free hydroarylation of unactivated alkynes was achieved by combining a Brønsted acid catalyst and a two-phase solvent system consisting of 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP) and cyclohexane. This protocol is applicable to a wide variety of 2-alkynylbiaryls which leads to the synthesis of substituted phenanthrenes via 6-endo-selective ring closure. The biphasic system achieves
通过结合布朗斯台德酸催化剂和由1,1,1,3,3,3-六氟丙烷-2-醇(HFIP)和环己烷组成的两相溶剂体系,实现了未活化炔烃的无过渡金属无氢芳基化反应。该方案适用于多种2-炔基联芳基,其可通过6-内-选择性闭环合成取代的菲。双相体系通过适当地将阳离子中间体与中性化合物分离来实现高效的闭环。乙烯基碳正离子中间体在HFIP相中稳定,而底物和产物在环己烷相中分布以抑制分子间副反应。