Electrophilic substitution in indoles. Part 18. Cyclisation of N-acyltryptamines
作者:Kshetra M. Biswas、Anthony H. Jackson、Mozaina M. Kobaisy、Patrick V. R. Shannon
DOI:10.1039/p19920000461
日期:——
Cyclisation of Nb-acetyltryptamines 8 with trifluoroacetic anhydride, or pentafluoropropionic anhydride, affords spirocyclicindolines of types 14 and 15 in virtually quantitative yields. The mechanism of the reactions involves Cyclisation by ipso-attack at the 3-position of the indole nucleus, to form spirocyclic 3H-indoles 12 and 13, which subsequently undergo addition of the anhydride to the 1,2-double