Trimethylsilyl Trifluoromethanesulfonate Catalyzed Nucleophilic Substitution To Give <i>C</i>- and <i>N</i>-Glucopyranosides Derived from <scp>d</scp>-Glucopyranose
作者:Takashi Yamanoi、Yoshiki Oda
DOI:10.1055/s-2007-983882
日期:2007.10
This paper describes the synthesis of C- and N-glucopyranosides via trimethylsilyl trifluoromethanesulfonate catalyzed nucleophilic substitution of glucopyranosides, derived from d-glucopyranose, with methyl, ethyl, n-butyl, allyl, benzyl, and phenyl groups at the anomeric carbon centers. Generally, the reactions using allyltrimethylsilane, trimethylsilyl azide, trimethylsilyl cyanide, and 1-phenyl-1-(trimethylsiloxy)ethene as the nucleophiles in the presence of 20 mol% trimethylsilyl trifluoromethanesulfonate in acetonitrile at -40 °C smoothly proceeded with α-stereoselectivity to afford various C- and N-glucopyranosides in 78-99% yield. Although a decrease in the synthetic yields was observed for some reactions using glucopyranoses with allyl and benzyl groups at the anomeric carbon, the yields could be improved using glucopyranosyl acetates in the presence of 20 mol% trimethylsilyl trifluoromethanesulfonate in acetonitrile-dichloromethane (1:1) at -78 °C.
本文描述了通过三甲基硅基三氟甲磺酸盐催化的亲核取代反应合成C-和N-葡萄糖吡喃糖苷,该反应是通过将来自D-葡萄糖吡喃糖的葡萄糖吡喃糖苷与甲基、乙基、正丁基、烯丙基、苄基和苯基等在异头碳中心进行的。通常,在-40°C时,在20摩尔%的三甲基硅基三氟甲磺酸盐存在下,使用烯丙基三甲基硅烷、三甲基硅基叠氮化物、三甲基硅基氰化物和1-苯基-1-(三甲基硅氧基)乙烯作为亲核试剂的反应顺利进行,并表现出α立体选择性,产率在78-99%之间。尽管对于某些使用含有烯丙基和苄基的葡萄糖吡喃糖在异头碳的反应观察到了合成产率的下降,但在-78°C的氯乙烯-二氯甲烷(1:1)混合物中使用葡萄糖吡喃糖醋酸酯并在存在20摩尔%三甲基硅基三氟甲磺酸盐的条件下,产率可以得到改善。