1359716-09-8Relevant articles and documents
Nickel-catalyzed cyclization of ortho-iodoketoximes and ortho-iodoketimines with alkynes: Synthesis of highly substituted isoquinolines and isoquinolinium salts
Shih, Wei-Chun,Teng, Chu-Chun,Parthasarathy, Kanniyappan,Cheng, Chien-Hong
, p. 306 - 313 (2012/05/05)
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 1,3,4-trisubstituted isoquinoline products in moderate to excellent yields and high regioselectivity. The corresponding isoquinoline N-oxide was found to be the intermediate in the cyclization reaction pathway. In contrast, the reaction of ortho-haloketimines and alkynes under similar catalytic conditions in tetrahydrofuran at 70 °C for two hours gave 1,2,3,4-tetrasubstituted isoquinolinium salts in good to excellent yields. In the nickel of time: ortho-Haloketoximes and -ketimines undergo [4+2] cyclization reactions with alkynes, catalyzed by nickel complexes to give highly substituted isoquinolines and isoquinolinium salts, respectively, in good to excellent yields (see scheme).
