Hetero-Diels–Alder reactions of perfluoroalkyl thioamides with electron-rich 1,3-dienes: synthesis of new 2-aminosubstituted-3,6-dihydro-2H-thiopyrans and related compounds
作者:Oleksandr S. Kanishchev、Morgane Sanselme、Jean-Philippe Bouillon
DOI:10.1016/j.tet.2012.11.086
日期:2013.1
Hetero-Diels–Alder reactions of perfluoroalkyl thioamides with electron-rich 1,3-dienes such as 2,3-dimethylbutadiene, isoprene or penta-1,3-diene gave a simple and efficient access to new 2-aminosubstituted-3,6-dihydro-2H-thiopyrans. Three different procedures were used depending on the nature of the polyfluoroalkyl chains (RF=CF3, (CF2)nCF3, (CF2)4H) and on the nitrogen substituents of the thioamides
全氟烷基硫酰胺与富电子的1,3-二烯(例如2,3-二甲基丁二烯,异戊二烯或五,1,3-二烯)的杂狄尔斯-阿尔德反应使新的2-氨基取代的3,6的反应简单有效。 -二氢-2 H-硫代吡喃。根据多氟烷基链的性质(R F = CF 3,(CF 2)n CF 3,(CF 2)4 H)和硫代酰胺的氮取代基(R 1,R 2 = H,对-Tol,吗啉代,Ac)。此外,甲硅烷氧基二烯(1-或2-三甲基甲硅烷氧基-1,3-丁二烯和丹尼舍夫斯基二烯)与N-酰基,N-甲苯基三氟甲基硫代酰胺几乎在所有情况下均提供相应的3,6-二氢-2 H-噻喃或3-氧代-四氢噻喃。对于非对称的1,3-二烯,研究了反应的区域和立体化学(尤其是使用X射线衍射分析),表明与报道的氟代硫代羧基衍生物具有高度相似性。最后,两个甲硅烷基化的3,6-dihydro-2 H -thiopyrans经历了意外的碱基诱导的环收缩,得到了新的1,3-噻唑烷酮-4-酮。