Direct Carbon-Carbon Bond Formation via Chemoselective Soft Enolization of Thioesters: A Remarkably Simple and Versatile Crossed-Claisen Reaction Applied to the Synthesis of LY294002

Guoqiang Zhou, Daniel Lim and Don M. Coltart*

*Department of Chemistry, Duke University, Durham, North Carolina 27708, Email: don.coltartduke.edu

G. Zhou, D. Lim, D. M. Coltart, Org. Lett., 2008, 10, 3809-3812.

DOI: 10.1021/ol801498u (free Supporting Information)

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Abstract

Thioesters undergo chemoselective soft enolization and acylation by N-acylbenzotriazoles on treatment with MgBr₂·OEt₂ and i-Pr₂NEt to give β-keto thioesters without prior enolate formation. The reaction is conducted using untreated CH₂Cl₂ open to the air. The coupled products can be converted directly into β-keto esters, β-keto amides, and β-diketones under mild conditions.

see article for more examples

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Direct Carbon-Carbon Bond Formation via Soft Enolization: A Facile and Efficient Synthesis of 1,3-Diketones

D. Lim, F. Fang, G. Zhou, D. M. Coltart, Org. Lett., 2007, 9, 4139-4142.

A Facile and Efficient Direct Aldol Addition of Simple Thioesters

J. M. Yost, G. Zhou, D. M. Coltart, Org. Lett., 2006, 8, 1503-1506.

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Key Words

Claisen Condensation, β-keto carboxylic compounds

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ID: J54-Y2008-2390