Structural and Spectroscopic Evidence for the Occurrence ofgauche-Betaine Intermediates in the Thio Wittig Reaction
作者:Carsten Puke、Gerhard Erker、Birgit Wibbeling、Roland Fröhlich
DOI:10.1002/(sici)1099-0690(199908)1999:8<1831::aid-ejoc1831>3.0.co;2-r
日期:1999.8
averaged 1JPCipso(aryl) coupling constant was used to elucidate the characteristic structural properties of Wittig and thio Wittig intermediates derived by treatment of the series Ph3PCH2 (2a), Ph2MePCH2 (2b), and PhMe2PCH2 (2c) with bis(p-methoxyphenyl) ketone to give 3 or benzophenone (to give 3′) or bis(p-methoxyphenyl) thioketone (to give 5), respectively. The oxaphosphetane series 3′a–3′c shows a strong
叶立德(环丙基)3PCH2 与 Michler 硫酮 SC(C6H4NMe2)2 在 [D5] 吡啶中的反应得到硫代维蒂希中间体 [(环丙基)3P+–CH2–CAr2–S–](11;31P NMR:δ = +27.7) . 化合物 11 通过 X 射线衍射表征并显示出具有 S–C–C–P 二面角为 52.9(3)° 和 P…S 分离度为 3.312(2) 的 gauche-甜菜碱型结构A. 特征平均 1JPCipso(aryl) 偶联常数用于阐明 Wittig 和 thio Wittig 中间体的特征结构性质,这些中间体是通过用 bis(p) 处理系列 Ph3PCH2 (2a)、Ph2MePCH2 (2b) 和 PhMe2PCH2 (2c) 而得到的-甲氧基苯基)酮分别得到 3 或二苯甲酮(得到 3')或双(对甲氧基苯基)硫酮(得到 5)。oxaphosphetane 系列 3'a–3'c