Platinum-catalyzed intramolecular alkylation of indoles with unactivated olefins.
Journal Article (Journal Article)
Reaction of 1-methy-2-(4-pentenyl)indole (1) with a catalytic amount of PtCl2 (2 mol %) in dioxane that contained a trace of HCl (5 mol %) at 60 degrees C for 24 h led to the isolation of 4,9-dimethyl-2,3,4,9-tetrahydro-1H-carbazole (2) in 92% yield. Platinum-catalyzed cyclization of 2-(4-pentenyl)indoles tolerated substitution at each position of the 4-pentenyl chain. Furthermore, the protocol was applicable to the synthesis of tetrahydro-beta-carbolinones and was effective for cyclization of unprotected indoles. 2-(3-Butenyl)indoles underwent platinum-catalyzed cyclization with exclusive 6-endo-trig regioselectivity. Mechanistic studies established a mechanism for the platinum-catalyzed cyclization of 2-alkenyl indoles involving nucleophilic attack of the indole on a platinum-complexed olefin.
Full Text
Duke Authors
Cited Authors
- Liu, C; Han, X; Wang, X; Widenhoefer, RA
Published Date
- March 2004
Published In
Volume / Issue
- 126 / 12
Start / End Page
- 3700 - 3701
PubMed ID
- 15038708
Pubmed Central ID
- 15038708
Electronic International Standard Serial Number (EISSN)
- 1520-5126
International Standard Serial Number (ISSN)
- 0002-7863
Digital Object Identifier (DOI)
- 10.1021/ja031814t
Language
- eng