Stereoselective Synthesis of Fluoroalkenoates and Fluorinated Isoxazolidinones: N-Substituents Governing the Dual Reactivity of Nitrones
作者:G. K. Surya Prakash、Zhe Zhang、Fang Wang、Martin Rahm、Chuanfa Ni、Marc Iuliucci、Ralf Haiges、George A. Olah
DOI:10.1002/chem.201303509
日期:2014.1.13
α‐Fluoroalkenoates and 4‐fluoro‐5‐isoxazolidinones are of vast interest due to their potential biological applications. We now demonstrate the syntheses of (E)‐α‐fluoroalkenoates and 4‐fluoro‐5‐isoxazolidinones by the reactions between nitrones and α‐fluoro‐α‐bromoacetate. By altering N‐substituents in nitrones, (E)‐α‐fluoroalkenoates and 4‐fluoro‐5‐isoxazolidinones can be achieved, respectively, with
The modifiedJuliaolefinationreaction has been applied to develop a stereoselective synthesis of fluoroalkenoate derivatives from a fluorobenzothiazolyl sulfone and aldehydes or a ketone. The olefinationreaction can be achieved by using a variety of bases. DBU and DBU in the presence of MgBr2 were found to be the most efficient systems to prepare either (Z)- or (E)-alkenoates in moderate to excellent
The One-Pot Wittig Reaction: A Facile Synthesis of α,β-Unsaturated Esters and Nitriles by Using Nanocrystalline Magnesium Oxide
作者:Boyapati M. Choudary、Koosam Mahendar、M. Lakshmi Kantam、Kalluri V. S. Ranganath、Taimur Athar
DOI:10.1002/adsc.200606001
日期:2006.9
Nanocrystalline magnesium oxide was found to be an effective heterogeneous, solid base catalyst for the one-pot Wittig reaction to afford α,β-unsaturatedesters and nitriles in excellent yields with high E-stereoselectivity in the presence of triphenylphosphine under mild conditions.
A Facile and Mild Approach for Stereoselective Synthesis of α-Fluoro-α,β-unsaturated Esters from α-Fluoro-β-keto Esters via Deacylation
作者:Wenbin Yi、Jinlong Qian、Meifang Lv、Chun Cai
DOI:10.1055/s-0034-1378917
日期:——
The highly stereoselective olefination reaction of α-fluoro-β-keto esters for the synthesis of α-fluoro-α,β-unsaturated esters has been developed. The olefination combines nucleophilic addition, intramolecular nucleophilic addition, and elimination in one step, as well as provides a facile synthetic approach to α-fluoro-α,β-unsaturated esters which are important units in many biologically active compounds
Microwave-Assisted One-Pot
Synthesis of α-Fluoro-α,β-Unsaturated
Esters under Solvent-Free Conditions
作者:Xiaochun Yu、Aishan Ren、Xiongjun Yang、Jing Hong
DOI:10.1055/s-2008-1078213
日期:——
A microwave-assisted approach for the synthesis of α-fluoro-α,β-unsaturated esters from ethyl bromofluoroacetate, aldehydes, and triphenylphosphine in the presence of Zn-Cu undersolvent-freeconditions was achieved. The reaction was accomplished within five minutes with good product yields.