Preparation of trifluoromethylated ynamines and their reactions with some electrophilic reagents
作者:Takashi Ishihara、Toshiya Mantani、Tsutomu Konno、Hiroki Yamanaka
DOI:10.1016/j.tet.2005.11.086
日期:2006.4
three-step procedure starting from commercially available 2,2,3,3,3-pentafluoropropanol. The reactions of these trifluoromethylated ynamines with some electrophiles, such as aldehydes, halogens or N-halosuccinimides (NXS), were investigated. The fluorinated ynamines reacted with aldehydes in the presence of a catalytic amount of Lewis acid to provide the corresponding α-(trifluoromethyl)-α,β-unsaturated
从市售的2,2,3,3,3-五氟丙醇开始,通过三步法制备N,N-二烷基(3,3,3-三氟-1-丙炔基)胺。研究了这些三氟甲基化的亚胺与某些亲电子试剂(如醛,卤素或N-卤代琥珀酰亚胺(NXS))的反应。在催化量的路易斯酸的存在下,氟化的乙胺与醛反应,以高至优异的产率和高的Z-立体选择性提供相应的α-(三氟甲基)-α,β-不饱和酰胺。这些乙胺与分子硼反应,用碳酸氢钠处理后,得到N,N-二烷基-2-溴-3,3,3-三氟丙酰胺的收率很高。与等分子量的NXS在乙腈水溶液中的反应还以良好或极好的收率得到了相应的2-卤代3,3,3-三氟丙酰胺。另一方面,在无水乙腈中乙胺与NXS的反应导致高收率形成加成产物。用在乙腈水溶液中等摩尔量的NX'S处理加成产物后,相应的2,2-二卤代(X,X')-3,3,3-三氟丙酰胺的产量接近定量。