通过在温和的条件下通过铜催化的磷化磷与烯基硼酸的氧化偶联反应,开发了一种可调谐策略,以高至极好的收率制备α,β-不饱和酯和α,β-不饱和γ-酮酯。不加水的反应得到α,β-不饱和酯,酮和酰胺,而α,β-不饱和γ-酮酯,1,4-α,β-不饱和二酮和α,β-不饱和γ-酮酰胺是使用5.0当量时获得。水。高2 O 18标记实验表明,水在α,β-不饱和γ-酮酸酯的形成中起着重要作用。在机理研究的基础上,提出了α,β-不饱和酯和α,β-不饱和γ-酮酯的合理形成机理。salts盐也可以代替磷化磷化物直接用作偶联伴侣。该反应表现出广泛的底物范围,良好的官能团耐受性,良好的区域选择性和多种偶联产物。
A Catalytic Cross‐Olefination of Diazo Compounds with Sulfoxonium Ylides
作者:James D. Neuhaus、Adriano Bauer、Alexandre Pinto、Nuno Maulide
DOI:10.1002/anie.201809934
日期:2018.12.3
A ruthenium‐catalysed cross‐olefination of diazo compounds and sulfoxonium ylides is presented. Our reaction design exploits the intrinsic difference in reactivity of diazo compounds and sulfoxonium ylides as both carbene precursors and nucleophiles, which results in a highly selective reaction.
Chiral Bicyclic Guanidine as a Versatile Brønsted Base Catalyst for the Enantioselective Michael Reactions of Dithiomalonates and β-Keto Thioesters
作者:Weiping Ye、Zhiyong Jiang、Yujun Zhao、Serena Li Min Goh、Dasheng Leow、Ying-Teck Soh、Choon-Hong Tan
DOI:10.1002/adsc.200700326
日期:2007.11.5
A chiral bicyclic guanidine was developed as a versatile Brønsted base catalyst for the enantioselective Michael reactions of dithiomalonates and β-keto thioesters using a range of acceptors including maleimides, cyclic enones, furanone and acyclic 1,4-dicarbonylbutenes.
Diastereo- and enantioselective synthesis of α,β-epoxyketones using aqueous NaOCl in conjunction with dihydrocinchonidine derived phase-transfer catalysis at room temperature. Scope and limitations
作者:Barry Lygo、Stuart D. Gardiner、Michael C. McLeod、Daniel C. M. To
DOI:10.1039/b706546a
日期:——
In this paper we present studies into the scope and limitations of asymmetric PTC epoxidation of enones and the oxidationâepoxidation of allylic alcohols using aqueous NaOCl in conjunction with a dihydrocinchonidine derived quaternary ammoniumsaltcatalyst.
A highly enantioselective Friedel–Craftsreaction of activatedphenols with (E)-4-oxo-4-arylbutenoates has been developed with the N,N′-dioxide-scandium(III) complex as the catalyst. A variety of (E)-4-oxo-4-arylbutenoates were found to be suitable substrates for the reaction. The desired products were obtained in moderate to high yields (up to 98%) and excellent enantioselectivities (up to 97% ee)
the enantioselective synthesis of complex tricyclo[3.2.2.0]nonenes through the Diels–Alder reaction is reported. Utilizing racemic norcaradienes prepared from the visible-light-mediated dearomative cyclopropanation of m-xylene as dienes and enone derivatives as dienophiles, the overall process represents a kinetic asymmetric transformation in the presence of a chiral cobalt(II) complex of chiral N,N′-dioxide