Nickel-Catalyzed Cyclization of ortho-Iodoketoximes and ortho-Iodoketimines with Alkynes: Synthesis of Highly Substituted Isoquinolines and Isoquinolinium Salts
作者:Wei-Chun Shih、Chu-Chun Teng、Kanniyappan Parthasarathy、Chien-Hong Cheng
DOI:10.1002/asia.201100834
日期:2012.2.6
A convenient method for the synthesis of highly substituted isoquinolines and isoquinolinium salts by the nickel‐catalyzed cyclization of ortho‐haloketoximes and ‐ketimines, respectively, with alkynes is described. The reaction of ortho‐haloketoximes and various alkynes in the presence of [Ni(PPh3)2Br2] and zinc powder in a mixture of acetonitrile and tetrahydrofuran at 80 °C for 15 hours gave 1,3
描述了一种方便的方法,该方法通过炔烃分别通过邻位卤代酮肟和酮缩酮的镍催化环化反应来合成高度取代的异喹啉和异喹啉鎓盐。在[Ni(PPh 3)2 Br 2 ]和锌粉在乙腈和四氢呋喃的混合物中,邻卤代酮肟和各种炔烃在80°C下反应15小时,得到1,3,4-三取代异喹啉产物具有中等至优异的产量和较高的区域选择性。发现相应的异喹啉N-氧化物是环化反应途径中的中间体。相反,邻位反应卤代亚胺和炔烃在相似的催化条件下,在四氢呋喃中于70°C加热2小时,可得到1,2,3,4-四取代的异喹啉鎓盐,收率很好。