Deep eutectic solvent (DES) was employed as dual solvent/catalyst in the green synthesis of α-diazocarbonyl compounds using aldol-type coupling. α-Diazocarbonyl compounds are important syntheticintermediates with useful application for synthesis of amino alcohols and acids and many natural products. Moreover, the method is environmentally friendly because of avoidance of toxic solvents or hazardous
Stereoselective Reduction of β-Hydroxy α-Ketoesters: A Concise Synthesis of<i>anti</i>-α,β-Dihydroxy Esters
作者:Jianbo Wang、Mingyi Liao、Wengang Yao
DOI:10.1055/s-2004-831210
日期:——
A new synthetic route to anti-α,β-dihydroxy esters has been developed. The new method consists of three steps starting from an aldehyde: the nucleophilic condensation with ethyl diazoacetate, oxidation with dimethyldioxirane, and stereoselective reduction with NaBH4.
DBU-catalyzed condensation of acyldiazomethanes to aldehydes in water and a new approach to ethyl β-hydroxy α-arylacrylates
作者:Fengping Xiao、Yu Liu、Jianbo Wang
DOI:10.1016/j.tetlet.2006.12.062
日期:2007.2
DBU-catalyzed condensation of ethyl diazoacetate (EDA) with aldehydes in pure water afforded corresponding beta-hydroxy alpha-diazo carbonyl compounds. The beta-hydroxy group of the products was further converted into beta-siloxy group. The Rh(II)-catalyzed reaction of the beta-aryl beta-siloxy alpha-diazo carbonyl compounds gave 1,2-aryl shift products predominantly. The three-step transformation constitutes an efficient synthesis of ethyl beta-hydroxy alpha-arylacrylates. (c) 2006 Elsevier Ltd. All rights reserved.
Safe Generation and Direct Use of Diazoesters in Flow Chemistry
A safe and fast method for the production of beta-hydroxy-alpha-diazoesters in continuous flow technology is described. The synthesis involves the formation of ethyl diazoacetate in situ and the addition to several aldehydes in a two-step continuous flow microreactor setup. Rhodium acetate catalyzes a subsequent 1,2-hydride shift to give access to beta-keto esters in a three-step sequence.