Visible-Light-Mediated α-Arylation of Enol Acetates Using Aryl Diazonium Salts
作者:Thea Hering、Durga Prasad Hari、Burkhard König
DOI:10.1021/jo301984p
日期:2012.11.16
light mediates efficiently the α-arylation of enol acetates by aryl diazonium salts under mild conditions using [Ru(bpy)3]Cl2 as a photoredox catalyst. The broad scope of the reaction toward various diazonium salts and enol acetates was explored. The application of this reaction in the concise synthesis of 2-substituted indoles was demonstrated
The reaction of tributyltin enolates, prepared from tributyltin methoxide and enol acetates in situ, with bromobenzene in the presence of a catalytic amount of PdCl2(o-tolyl3P)2 was found to give α-phenyl ketones in good yields with essentially complete retetion of the acetate regiochemistry.
Synthesis of 1,4-Diketones from β-Oxo Esters and Enol Acetates by Cerium-Catalyzed Oxidative Umpolung Reaction
作者:Irina Geibel、Jens Christoffers
DOI:10.1002/ejoc.201600057
日期:2016.2
esters are converted with enol acetates in a cerium‐catalyzed, oxidative Umpolung reaction to furnish 1,4‐diketones with up to 95 % yield. Atmospheric oxygen is the oxidant in this process, which can be regarded as ideal from economic and ecological points of view. Further advantages of this new C–C coupling reaction are its operational simplicity and the application of nontoxic and inexpensive CeCl3
Highly Enantioselective Rh-Catalysed Hydrogenation of 1-Alkyl Vinyl Esters Using Phosphine-Phosphoramidite Ligands
作者:Tina Maria Konrad、Pascal Schmitz、Walter Leitner、Giancarlo Franciò
DOI:10.1002/chem.201303066
日期:2013.9.27
MatPhos, a good mate for hard tasks: The asymmetric hydrogenation of 1‐alkyl vinyl esters, thwarted so far by mediocre ee values and low activities, can now be achieved with MatPhos/Rh catalysts with ee values of 96–99 % for a variety of substrates at low catalyst loadings (0.1–1 mol %) and under mild conditions (5–20 bar H2, room temperature). After hydrolysis, the corresponding chiral secondary alkyl
MatPhos,是完成艰苦任务的理想伴侣:迄今为止,由于中等ee值和低活性,阻碍了1-烷基乙烯基酯的不对称氢化,现在可以使用ee值为96–99%的MatPhos / Rh催化剂来实现在低催化剂负载量(0.1-1 mol%)和温和条件(5-20 bar H 2,室温)下制备底物。水解后,可以高对映体纯度获得相应的手性仲烷基醇,为获得这一重要产品类别提供了一条通用而实用的途径。
1-ALKENYLATION ON α-POSITION OF KETONE: PALLADIUM-CATALYZED REACTION OF TIN ENOLATES AND 1-BROMO-1-ALKENES
作者:Masanori Kosugi、Isao Hagiwara、Toshihiko Migita
DOI:10.1246/cl.1983.839
日期:1983.6.5
The reaction of tributyltinenolates, prepared from tributyltin methoxide and enol acetates in situ, with 1-bromo-1-alkenes in the presence of a catalytic amount of PdCl2(o-tolyl3P)2 was found to give the derivatives of allyl ketone in good yields.