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
Organic Letters2008Vol. 10(17), pp. 3809–3812
Citations Over TimeTop 11% of 2008 papers
Abstract
Thioesters undergo chemoselective soft enolization and acylation by N-acylbenzotriazoles on treatment with MgBr2 x OEt2 and i-Pr2NEt to give beta-keto thioesters. Prior enolate formation is not required, and the reaction is conducted using untreated CH2Cl2 open to the air. The coupled products are stable synthetic equivalents of beta-keto acids and can be converted directly into beta-keto esters, beta-keto amides, and beta-diketones under mild conditions. The utility of this carbon-carbon bond-forming method is shown through the synthesis of the PI3-K inhibitor LY294002.
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