Isothiourea-catalysed transfer hydrogenation of α,β-unsaturated para-nitrophenyl esters

TETRAHEDRON

卷:78

Article

Wu, Jiufeng¹  Young, Claire M.¹  Smith, Andrew D.¹ 

[1] Univ St Andrews, Sch Chem, EaStCHEM, St Andrews KY16 9ST, Fife, Scotland

关键词: Transfer hydrogenation;    Isothiourea;    Organocatalysis;    Hantzsch ester;   

DOI  :  10.1016/j.tet.2020.131758

来源: Elsevier

【 摘 要 】

A protocol for the isothiourea-catalysed transfer hydrogenation of alpha,beta-unsaturated para-nitrophenyl esters using Hantzsch ester has been developed. Good to excellent yields are observed using alpha,beta-unsaturated aryl esters bearing electron-withdrawing beta-substituents. The aryl ester products can either be isolated directly in moderate to excellent yields (7 examples, 16-98%) or converted to the corresponding methyl esters (2 examples, 68-70% yield) or benzyl amides (2 examples, 44-88% yield) after in situ reaction of the hydrogenated ester with the appropriate nucleophile. Preliminary experiments showed that modest enantioinduction (76:24 er) is possible when a chiral isothiourea catalyst was used. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

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