Platinum-catalyzed intramolecular alkylation of indoles with unactivated olefins.

Published

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