Efficient and suitable preparation of N-sulfonyl-1,2,3,4-tetrahydroisoquinolines and ring analogues using recyclable H6P2W18O62·24H2O/SiO2 catalyst
作者:Gustavo Pasquale、Diego Ruiz、Juan Autino、Graciela Baronetti、Horacio Thomas、Gustavo Romanelli
DOI:10.1016/j.crci.2012.05.016
日期:2012.9
Résumé Silica gel-supported H6P2W18O62·24H2O is an efficient and recyclable catalyst for the synthesis of biologically important molecules. Several substituted N-sulfonyl-1,2,3,4-tetrahydroisoquinolines and ring analogues can be prepared in very good yields and purity by direct reaction of N-aralkylsulfonamides and sym-trioxane by a Pictet-Spengler reaction in the presence of a catalytic amount of silica gel-supported H6P2W18O62·24H2O. Reactions were performed in a low volume of toluene, at 70 °C and for a short time, typically 15 to 30 min. The title heterocyclic compounds were prepared in very good yields (60%–95%) using the described procedure results in a clean and useful alternative, which has the advantages of a greener methodology with operative simplicity, use of a reusable and non-corrosive solid catalyst, soft reaction conditions, low reaction times, and good yields.
摘要 硅胶支撑的 H6P2W18O62-24H2O 是一种高效且可回收的催化剂,可用于合成重要的生物分子。在一定量的硅胶支撑的 H6P2W18O62-24H2O 催化下,N-芳基磺酰胺与交三氧杂环己烷通过皮克泰-斯彭勒反应直接反应,可以制备出几种取代的 N-磺酰基-1,2,3,4-四氢异喹啉和环类似物,而且产率和纯度都非常高。反应在低浓度甲苯中进行,温度为 70 °C,时间很短,一般为 15 至 30 分钟。使用所述步骤制备的标题杂环化合物收率非常高(60%-95%),是一种清洁、有用的替代方法,具有操作简单、使用可重复使用的非腐蚀性固体催化剂、反应条件温和、反应时间短和收率高的优点。