Undecorated Cu(OAc)<sub>2</sub>-Catalyzed C(sp<sup>3</sup>)-C(sp<sup>3</sup>) Bond Formation through<i>para</i>-Hydroxy Group Triggered Remote Benzylic C(sp<sup>3</sup>)-H Bond Functionalization
作者:Jian-Gang Huang、Ying Guo、Yu-Dan Li、Hong-Wei Liu、Dao-Hua Liao、Ya-Fei Ji
DOI:10.1002/ejoc.201500706
日期:2015.8
The undecoratedCu(OAc)2-catalyzed para-hydroxy grouptriggered oxidative coupling of 2,6-disubstituted 4-cresols with fluorinated β-keto esters or malonates leading to benzylicC(sp3)–C(sp3) bondformation was investigated. This formal double C(sp3)–H coupling method features mild conditions, atom economy, ligand- and additive-free catalysis, and ambient air as the terminal oxidant. This ecofriendly
By utilising a chiral bicyclic guanidine as catalyst and triethylamine as additive, the first asymmetric Michael addition of α-fluoro-β-ketoesters to various cyclicenones has been successfully developed, affording a variety of Michael adducts with potential synthetic utilities with satisfactory stereoselectivity (up to 94 % ee and 4.3 : 1 dr).
作者:Serry R. F. Kagaruki、Tomoya Kitazume、Nobuo Ishikawa
DOI:10.1246/bcsj.54.3221
日期:1981.10
3-Alkyl(or aryl)-4-fluoro-5-hydroxypyrazoles and their 1-methyl derivatives were prepared by the reaction of methyl α-fluoro-β-alkyl(or aryl)-β-keto esters with hydrazine hydrate or methylhydrazine in ethanol. The reaction of arylhydrazines with α-fluoro-β-keto esters gave only hydrazones which could not be cyclized to pyrazoles.