Gold(I)-Catalyzed Intermolecular Hydroarylation of Alkenes with Indoles under Thermal and Microwave-Assisted Conditions
An efficient method for intermolecular hydroarylation of aryl and aliphatic alkenes with indoles using a combination of [(PR3)AuCl]/AgOTf as catalyst under thermal and microwave‐assisted conditions has been developed. The gold(I)‐catalyzed reactions of indoles with aryl alkenes were achieved in tolu...
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Published in | Chemistry : a European journal Vol. 14; no. 27; pp. 8353 - 8364 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Weinheim
WILEY-VCH Verlag
19.09.2008
WILEY‐VCH Verlag Wiley |
Subjects | |
Online Access | Get full text |
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Summary: | An efficient method for intermolecular hydroarylation of aryl and aliphatic alkenes with indoles using a combination of [(PR3)AuCl]/AgOTf as catalyst under thermal and microwave‐assisted conditions has been developed. The gold(I)‐catalyzed reactions of indoles with aryl alkenes were achieved in toluene at 85 °C over a reaction time of 1–3 h with 2 mol % of [(PR3)AuCl]/AgOTf as catalyst. This method works for a variety of styrenes bearing electron‐deficient, electron‐rich, and sterically bulky substituents to give the corresponding products in good to high yields (60–95 %). Under microwave irradiation, coupling of unactivated aliphatic alkenes with indoles gave the corresponding adducts in up to 90 % yield. Selective hydroarylation of terminal CC bond of conjugated dienes with indoles gave good product yields (62–81 %). On the basis of deuterium‐labeling experiments, a reaction mechanism involving nucleophilic attack of Au(I)‐coordinated alkenes by indoles is proposed.
Gold catalysis: Phosphine gold(I) complexes [(PR3)AuCl], in conjunction with silver triflate (AgOTf), catalyze intermolecular hydroarylation of aryl and aliphatic alkenes and conjugated dienes with indoles under thermal and microwave‐assisted conditions. This synthetic protocol provides convenient access to a variety of C3‐alkylated indoles under mild reaction conditions (see scheme). |
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Bibliography: | Hong Kong Research Grant Council - No. HKU 7052/07P University Grants Committee of the Hong Kong Special Administrative Region, China - No. AoE/P-10/01 ArticleID:CHEM200800040 The University of Hong Kong (University Development Fund) istex:4989A3DAEE51C29AA1A6F00CF22181A7CBE34454 ark:/67375/WNG-M6KSTG1F-V ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0947-6539 1521-3765 |
DOI: | 10.1002/chem.200800040 |