Reaction of indolin-2-ones with cerium(IV) ammonium nitrate
摘要:
The reaction of indolin-2-ones with CAN is studied. When the reaction is carried out in an alcohol as solvent, 3-alkoxyindolin-2ones are obtained in very good yields. If a non-nucleophilic solvent is used (THF, acetonitrile) 3-nitroxy derivatives are isolated. If the aromatic ring bears an electron-donating group, reactions are accompanied by aromatic ring nitration. (C) 2002 Elsevier Science Ltd. All rights reserved.
The intramolecular cyclisation of aryl radicals onto a pyrrole is studied. The cyclisation allows the synthesis of either the spiropyrrolidinyloxindole or the pyrrolo[3,2-c]quinoline skeleton depending on the nature of the protecting group at the N-pyrrole atom. The regiochemistry of the cyclisation is not affected by the substituents on the benzene ring. Some limitations on the utility of tosylmethyl-isocyanide in pyrrole synthesis are also reported. (C) 2002 Elsevier Science Ltd. All rights reserved.