Preparation of 2,3-disubstituted indoles by sequential Larock heteroannulation and silicon-based cross-coupling reactions

TETRAHEDRON

卷:65

Article; Proceedings Paper

Denmark, Scott E.¹  Baird, John D.¹ 

[1] Univ Illinois, Dept Chem, Roger Adams Lab, Urbana, IL 61801 USA

关键词: Cross-coupling;    Indoles;    Silanols;    Palladium catalysis;    Alkynes;   

DOI  :  10.1016/j.tet.2008.10.043

来源: Elsevier

【 摘 要 】

A simple and convergent synthesis of 2,3-disubstituted indoles has been developed using a sequential Larock indole synthesis and silicon-based, cross-coupling reaction. Substituted 2-iodoanilines reacted with an alkynyldimethylsilyl tert-butyl ether to afford indole-2-silanols under the Larock hetero-annulation conditions after hydrolysis. The corresponding sodium 2-indolylsilanolate salts successfully engaged in cross-coupling with aryl bromides and chlorides to afford multi-substituted indoles. The development of an alkynyldimethylsilyl tert-butyl ether as a masked silanol equivalent enabled a smooth heteroannulation process and the identification of a suitable catalyst/ligand combination provided for a facile cross-coupling reaction. (C) 2008 Elsevier Ltd. All rights reserved.

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