99763-20-9Relevant academic research and scientific papers
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
supporting information; experimental part, 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).
OXIDATIVE CYCLIZATION OF HALOBENZOPHENONE OXIMES TO 4,2'-IODONIA-3-PHENYL-1,2-BENZISOXAZOLE SALTS
Tolstaya, T. P.,Egorova, L. D.,Lisichkina, I. N.
, p. 392 - 396 (2007/10/02)
It is shown that the syn oximes of o-iodo- and o-, m-, and p-bromobenzophenones, under the influence of K2S2O8 in concentrated H2SO4, form the corresponding 3-aryl-1,2-benzisoxazoles as a result of oxidative cyclization. 3-(2-Iodophenyl)-1,2-benzisoxazole is oxidized by peracetic acid to the iodoso derivative which, upon heating in concentrated H2SO4, undergoes cyclization to the 4,2'-iodonia-3-phenyl-1,2-benzisoxazole cation.The iodide, bromide, and tetrafluoroborate of this cation were isolated.
