Directed ortho-metalation versus reductive amination in the preparation of polytopic, highly substituted, and sterically congested amine-S-arylthiocarbamates as thiophenol precursors
作者:Alexander Mondragón、Iván Monsalvo、Ignacio Regla、Marcos Flores-Alamo、Ivan Castillo
DOI:10.1016/j.tet.2013.08.044
日期:2013.11
migration of the thiocarbamoyl group to the ortho-position (Fries rearrangement), or nucleophilic attack of the carbonyl group by butyllithium, respectively. An alternative route employed 2,4-disubstituted phenols to obtain the corresponding salicylaldehydes, and subsequently the O-arylthiocarbamates for Newman–Kwart thermal rearrangement (NKR). Finally, the formyl group on the S-arylthiocarbamates allowed
多齿胺的合成小号-arythiocarbamates物通过定向测试邻-lithiation 2,4-二取代的苯硫酚,或相应的ö和-小号-arylthiocarbamates通过脱质子或锂-溴交换,随后加入的亲电子N(CH 2 CH 2 X)3(X = Br,I)。在硫酚的情况下,去质子化在加入亲电试剂时产生三硫醚-胺。与O-和S-硫代氨基甲酸酯一起,反应导致硫代氨基甲酰基基团向邻位迁移。位置(Fries重排)或丁基锂对羰基的亲核攻击。另一种替代方法是使用2,4-二取代的苯酚获得相应的水杨醛,然后使用O-芳基硫代氨基甲酸酯进行Newman-Kwart热重排(NKR)。最后,S-芳基硫代氨基甲酸酯上的甲酰基允许还原性胺化以将具有胺和S-硫代氨基甲酸酯基的多位化合物组装。