Rh-catalyzed asymmetric hydrogenation of α-aryl-β-alkylvinyl esters with chiral ferrocenylphosphine-phosphoramidite ligand
作者:Chao Dong、Dao-Sheng Liu、Lei Zhang、Xiang-Ping Hu
DOI:10.1016/j.tetlet.2020.152763
日期:2021.2
An enantioselective Rh-catalyzedhydrogenation of E/Z mixtures of trisubstituted vinyl esters has been disclosed. With a combination of [Rh(COD)2]BF4 and a structurally fine-tuning chiral ferrocenylphosphine-phosphoramidite ligand as the catalyst, a variety of E/Z mixtures of α-aryl-β-alkylvinyl esters have been successfully hydrogenated in high yields and with good to high enantioselectivities (up
reagents (trifluoromethyl)(4-nitrophenyl)bis(carbomethoxy)methylide (1g) and (trifluoromethyl)(3-chlorophenyl)bis(carbomethoxy)methylide (1j) through structure-activity study was described. Under mild conditions, reagent 1g reacted with β-ketoesters and silyl enol ethers to give α-trifluoromethylated-β-ketoesters or α-trifluoromethylated ketones in high yields. In addition, reagent 1g could serve as
PQS-enabled visible-light iridium photoredox catalysis in water at room temperature
作者:Mei-jie Bu、Chun Cai、Fabrice Gallou、Bruce H. Lipshutz
DOI:10.1039/c7gc03866f
日期:——
An amphoteric PQS-attached photocatalyst has been prepared that undergoes self-aggregation in water into nanomicelles. This covalently bound species enables Ir-based photoredoxcatalysis to be conducted in the absence of additives or co-solvents. Representative reactions are described using this new catalytic system, which require no additional investment of external energy in the form of heating or
METHODS OF PREPARING a,ß-UNSATURATED OR a-HALO KETONES AND ALDEHYDES
申请人:International Flavors & Fragrances Inc.
公开号:US20170174607A1
公开(公告)日:2017-06-22
Copper(II) bromide mediated oxidation of acylated enol and use of the reaction in the synthesis of α,β-unsaturated or α-bromo ketones or aldehydes are disclosed. The method provides an efficient and practical process for manufacturing dehydrohedione (DHH) and many other versatile α,β-unsaturated or α-bromo ketones or aldehydes in large scales to avoid using precious metal compounds.
Highly efficient Cu(I)-catalyzed trifluoromethylation of aryl(heteroaryl) enol acetates with CF3 radicals derived from CF3SO2Na and TBHP at room temperature
An efficient method for the Cu(I)-catalyzed synthesis of α-trifluoromethyl ketones via the addition of CF3 to aryl(heteroaryl) enolacetates by using the readily available CF3SO2Na (Langlois reagent) has been developed. The reaction is experimentally simple and carried out at room temperature, providing good to excellent yields with wide functional group tolerance.
通过加入CF的对α-三氟甲基酮的铜(I)催化合成的有效方法3至芳基通过使用容易获得的CF(杂芳基)乙酸酯烯醇3 SO 2 Na(上兰洛伊斯试剂)已被开发。该反应是简单的实验,并在室温下进行,以优异的产率提供了良好的与宽官能团耐受性。