Catalysis in Water: Aldol-Type Reaction of Aldehydes and Imines with Ethyl Diazoacetate Catalyzed by Highly Basic Magnesium/Lanthanum Mixed Oxide
作者:M. Lakshmi Kantam、V. Balasubrahmanyam、K. B. Shiva Kumar、G. T. Venkanna、F. Figueras
DOI:10.1002/adsc.200600597
日期:2007.8.6
Magnesium/lanthanum mixed oxide is an effective heterogeneous catalyst for aldol-type condensation of aldehydes and imines with ethyl diazoacetate (EDA) at room temperature in water to afford corresponding β-hydroxy-α-diazo carbonyl compounds and β-amino-α-diazo carbonyl compounds in good yields. The catalyst is recovered and reused for several cycles with consistent activity.
One-pot synthesis of α-diazo-β-hydroxyesters under phase-transfer catalysis and application to the catalytic asymmetric aldol reaction
作者:Shigeru Arai、Kazuya Hasegawa、Atsushi Nishida
DOI:10.1016/j.tetlet.2003.11.083
日期:2004.1
The one-pot (three steps) synthesis of α-diazo-β-hydroxyesters from tosyl chloride under phase-transfercatalysis is described. The catalytic asymmetric aldol reaction between a diazoester and aldehydes was also investigated and gave moderate to good enantioselectivity.
CuSO4-catalyzed diazo decomposition in water: a practical synthesis of β-keto esters
作者:Mingyi Liao、Jianbo Wang
DOI:10.1016/j.tetlet.2006.10.059
日期:2006.12
CuSO4 was found to be an efficient catalyst for the diazo decomposition of β-hydroxy α-diazoesters in water. 1,2-H shift occurred efficiently to give β-ketoesters in high yields. No O–H bond insertion products were identified.
Synthesis of α-diazo-β-hydroxyesters through a one-pot protocol by phase-transfer catalysis: application to enantioselective aldol-type reaction and diastereoselective synthesis of α-amino-β-hydroxyester derivatives
作者:Kazuya Hasegawa、Shigeru Arai、Atsushi Nishida
DOI:10.1016/j.tet.2005.11.028
日期:2006.2
The one-pot synthesis of α-diazo-β-hydroxyesters from sodium azide under phase-transfer-catalyzed conditions has been achieved. This protocol includes three different chemical transformations promoted by a single catalyst in each step to give products in good to excellent yields. The reaction was applied to a catalytic asymmetric aldol-type reaction using α-diazoesters with aldehydes in the presence
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.