Synthesis of Symmetrical and Unsymmetrical 2,5-Bis(trialkylsilyl)furans and 2,6-Bis(trialkylsilyl)-4H-pyrans from 1,4- and 1,5-Bis(acylsilanes)
作者:Jean-Philippe Bouillon、Damien Saleur、Charles Portella
DOI:10.1055/s-2000-6284
日期:——
2,5-Bis(trialkylsilyl)furans and 2,6-bis(trialkylsilyl)-4H-pyrans have been synthesized by cyclodehydration of 1,4- and 1,5-bis(acylsilanes) under p-toluenesulfonic acid catalysis. The 1,4-bis(acylsilanes) have been prepared from 1,2-bis(1,3-dithian-2-yl)ethane according to the reaction sequence metallation-silylation-dethioketalization. The 1,5-bis(acylsilanes) have been prepared from 1,3-bis(1,3-dithian-2-yl)propane by a similar strategy or from a SN reaction of 1,3-dihalopropanes with 2-trialkylsilyl-2-lithio-1,3-dithiane and deprotection. The method allows efficient preparation of symmetrical as well as unsymmetrical bis(silylated) heterocycles.
通过1,4-和1,5-双(酰基硅烷)在对甲苯磺酸催化下环化脱水合成了2,5-双(三烷基甲硅烷基)呋喃和2,6-双(三烷基甲硅烷基)-4H-吡喃。 1,4-双(酰基硅烷)由1,2-双(1,3-二噻烷-2-基)乙烷按照金属化-甲硅烷基化-脱硫缩酮化反应顺序制备。 1,5-双(酰基硅烷)是由1,3-双(1,3-二噻吩-2-基)丙烷通过类似的策略或通过1,3-二卤代丙烷与2-三烷基甲硅烷基的SN反应制备的。 2-锂-1,3-二噻烷和脱保护。该方法可以有效制备对称和不对称双(甲硅烷基化)杂环。