Development of the Enantioselective Addition of Ethyl Diazoacetate to Aldehydes: Asymmetric Synthesis of 1,2-Diols
作者:Barry M. Trost、Sushant Malhotra、Philipp Koschker、Pascal Ellerbrock
DOI:10.1021/ja206995s
日期:2012.2.1
A novel synthetic strategy toward the asymmetric synthesis of vicinal diols bearing a tertiary center is presented. The method encompasses the dinuclear Mg-catalyzed asymmetric addition of ethyldiazoacetate into several aldehydes, oxidation of the diazo functionality, and diastereoselective alkyl transfer of various organometallics into the resulting chiral β-hydroxy-α-ketoesters to afford a diverse
Abstract The aldoladdition of acyldiazomethane with aromatic aldehydes, vinyl aldehyde and aliphatic aldehydes was carried out efficiently in the presence of MgI2 etherate and iPr2EtN (DIPEA) using untreated reagent-grade CH2Cl2 under atmospheric conditions in good to excellent yields. Iodide counterion and a non-coordinating reaction media (i.e. CH2Cl2) are among the critical factors for the unique
Directaldolcondensation of various aromatic, heteroaromatic, α,β-unsaturated aldehydes and aliphatic aldehydes with acyldiazomethane was realized using MgI2 etherate (MgI2·(Et2O)n) as a promoter in the presence of diisopropyl amine (DIPEA) in excellent yields in a short time under mild conditions with high chemoselectivity. Iodide counterion, and a non-coordinating less ploar reaction media (i.e
KF/Nano-clinoptilolite Catalyzed Aldol-Type Reaction of Aldehydes with Ethyl Diazoacetate
作者:Javad Balou、Mohammad A. Khalilzadeh、Dariush Zareyee
DOI:10.1007/s10562-017-2158-6
日期:2017.10
nano-clinoptilolite (KF/CP NPs) was used as an excellent catalytic system for direct aldol-type condensation of aldehydes with ethyl diazoacetate under solvent-less conditions. A variety of α-diazo carbonyl derivatives were prepared in good to excellent yields in short reaction times.Graphical Abstract
Acid-catalyzed decomposition of diazocarbonyl compounds triggers a wide range of transformations leading to synthetically useful building blocks with high diversity. In this field, the chemistry of α-diazo-β-hydroxy ester substrates is largely dominated by migration processes. We describe herein a new approach to original mixed monosilyl acetals from O-protected α-diazo-β-hydroxy-β-aryl esters and alcohols