An Improved Synthesis Route to Functionalized 2-Alkyn-1-ylboronates: Useful Intermediates for the Preparation of α-Allenic Alcohols
作者:Chandra D. Roy、Raman Soundararajan、Herbert C. Brown
DOI:10.1007/s00706-007-0769-0
日期:2008.3
yields by reacting various acyclic and cyclic (iodomethyl)boronates with various alkynyllithium salts. Amongst various (iodomethyl)boronates studied, 2-(iodomethyl)-1,3,2-dioxa-4,4,5,5-tetramethylborolane provided improved chemical yields of 2-alkyn-1-ylboronates with pyran- and triisopropylsilyl-substituted alkynyllithium salts. 2-Alkyn-1-ylboronate bearing an acid sensitive structure (pyran) was successfully
通过使各种无环和环状(碘甲基)硼酸酯与各种炔基锂盐反应,可以高收率成功制备官能化的2-炔基-1-基硼酸酯。在研究的各种(碘甲基)硼酸酯中,2-(碘甲基)-1,3,2-二氧杂-4,4,5,5-四甲基硼烷提供了吡喃-和三异丙基甲硅烷基取代的2-炔-1-基硼酸酯的化学产率提高炔基锂盐。成功合成了带有酸敏感结构(吡喃)的2-炔-1-基硼酸酯,这在以前报道的反应条件下很难实现。源自频哪醇(碘甲基)硼酸酯的“酸酯”配合物异常快速的重排,抑制副产物的形成以及频哪醇2-炔基-1-基硼酸酯的稳定性是该协议的一些显着优点。就较温和的反应条件,官能团的相容性和操作的简便性而言,该新方法为现有方法提供了一种简单便捷的替代途径。通过使频哪醇2-炔基-1-基硼酸酯与苯甲醛反应来证明这类2-炔基-1-基硼酸酯的合成范围,从而以良好的产率和区域选择性生成α-烯丙醇。