Platinum-catalyzed intramolecular alkylation of indoles with unactivated olefins

被引:160
作者
Liu, C [1 ]
Han, XQ [1 ]
Wang, X [1 ]
Widenhoefer, RA [1 ]
机构
[1] Duke Univ, Paul M Gross Chem Lab, Durham, NC 27708 USA
关键词
D O I
10.1021/ja031814t
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
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 °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-β-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. Copyright © 2004 American Chemical Society.
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页码:3700 / 3701
页数:2
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