Synthesis of tetra-substituted imidazoles and 2-imidazolines by Ni(0)-catalyzed dehydrogenation of benzylic-type imines
作者:Adrian Tlahuext-Aca、Oscar Hernández-Fajardo、Alma Arévalo、Juventino J. García
DOI:10.1039/c4dt02313g
日期:——
performed to yield asymmetrical tetra-substituted imidazoles and 2-imidazolines. This was achieved with a single operational step while maintaining good selectivity and atom economy. The catalytic system shows low to moderate tolerance for fluoro-, trifluoromethyl-, methyl-, and methoxy-substituted benzylic-type imines. In addition, the substitution pattern at the N-heterocyclic products was easily
Ni(0)催化的苄型亚胺脱氢反应可制得不对称的四取代的咪唑和2-咪唑啉。这是通过一个单一的操作步骤即可实现的,同时保持了良好的选择性和原子经济性。催化体系对氟,三氟甲基,甲基和甲氧基取代的苄基亚胺具有低至中等的耐受性。另外,通过适当地选择起始有机底物中的R-基团,可以容易地控制N-杂环产物上的取代模式。基于实验观察,我们提出了一种反应机理,其中苄基C(sp 3)–H键的活化和插入步骤在该镍催化的有机转化中起关键作用。