Lewis Acid Catalyzed Indole Synthesis via Intramolecular Nucleophilic Attack of Phenyldiazoacetates to Iminium Ions
作者:Lei Zhou、Michael P. Doyle
DOI:10.1021/jo902089e
日期:2009.12.4
Lewis acids catalyze the cyclization of methyl phenyldiazoacetates with an ortho-imino group, prepared from o-aminophenylacetic acid, to give 2,3-substituted indoles in quantitative yields.
Synthesis of Substituted Indole-3-carboxylates by Iron(II)-Catalyzed Domino Isomerization of 3-Alkyl/aryl-4-aryl-5-methoxyisoxazoles
strategy. The iron(II)-catalyzed domino isomerization of 3-alkyl/aryl-4-arylisoxazoles provides a selective access to a wide range of structurally diverse highly substituted indole-3-carboxylates. The operational simplicity, high atom efficiency, and the use of stable starting materials and an inexpensive and low-toxicity catalyst are some of the attractive features of this tandem double ring-opening–ring-closure
one-pot sequence of N-alkylation, saponification and methoxyamidation, and final intramolecular oxidative C–N bond formation. The underpinning of the strategy entails Pd(OAc)2/Cu(OAc)2-mediated oxidative C(sp2)–C(sp2) bond formation and I(III)-mediated oxidative C(sp2)–N bond formation.