F. S. Melkonyan

Synthesis of N-substituted indole-3-carboxylic acid derivatives via Cu(I)-catalyzed intramolecular amination of aryl bromides.

A variety of N-alkylated and N-arylated derivatives of methyl 1 H-indole-3-carboxylate were synthesized efficiently via Ullmann-type intramolecular arylamination, using the CuI-K 3PO 4-DMF system. This catalytic amination procedure can be performed with good to high yields under mild conditions under an air atmosphere.

One-pot synthesis of substituted indoles via titanium(IV) alkoxide mediated imine formation – copper-catalyzed N-arylation

Readily accessible o-bromobenzylketones and primary alkyl amines and anilines were used for the construction of substituted indoles in good to excellent yields. The sequence involves a titanium-mediated reaction of ketones with amines to afford imines and subsequent intramolecular cyclization into indoles employing copper catalysis. The two-step protocol allows for the preparation of indoles bearing both N-alkyl and N-aryl groups as well as N-unsubstituted indoles without isolation of the intermediates and is tolerant of a wide range of functionality.

New strategies for the synthesis of N-alkylated indoles (Review)

New data, mostly published in the last five years, on methods for the synthesis of N-alkylated indoles both as a result of direct introduction of the alkyl substituent at the nitrogen atom and by construction of the indole heterocyclic system are reviewed. Only examples of indole derivatives containing branched, sterically hindered, and chiral alkyl substituents at the nitrogen atom are discussed.

A simple and practical synthesis of methyl benzo[b]furan-3-carboxylates

Abstract – A simple and practical two-step procedure for the preparation of 2-unsubstituted 1-benzo[ b ]furan-3-carboxylic acid methyl esters is described. The procedure uses the copper-catalyzed intramolecular C–O bond formation and provides an efficient route to the title compounds in good to excellent yields. INTRODUCTION Benzo[ b ]furan derivatives are an important class of heterocyclic compounds widely presented in nature. 1 Substituted benzo[ b ]furans are known to possess important biological properties and find application as pharmaceuticals, agricultural chemicals and in other fields of chemistry. 2 For this reason, numerous methods for the synthesis of benzo[ b ]furan derivatives 1-3 have been developed over the years and the majority of methods for selectively constructing benzo[ b ]furan ring system includes the transition metal-catalyzed transformations. 4 1-Benzo[ b ]furan-3-carboxylic acids ( 1 ) and their derivatives have found significant use as building blocks for the synthesis of pharmaceutically important molecules.