A new visible‐light photocatalytic arylsulfonylation and bicyclization of C(sp3)‐tethered 1,7‐enynes with sulfinic acids has been developed, delivering functionalized sulfone‐containing benzo[a]fluoren‐5‐ones with generally good yields. This Eosin Y‐catalyzed approach makes use of visible light as a safe and eco‐friendly energy source to drive cascade cyclization reactions, resulting in continuous
已开发出一种新的可见光光催化芳基磺酰化和C(sp 3)系的1,7-烯炔与亚磺酸的双环化,可提供官能化的含砜苯并[ a ]芴-5酮,且收率普遍良好。这种曙红Y催化方法利用可见光作为一种安全且生态友好的能源来驱动级联环化反应,从而导致连续的多个成键事件(包括C–S和C–C键)有效地构建多环连接的烷基芳基砜。
A Copper Catalyst with a Cinchona-Alkaloid-Based Sulfonamide Ligand for Asymmetric Radical Oxytrifluoromethylation of Alkenyl Oximes
作者:Xi-Tao Li、Qiang-Shuai Gu、Xiao-Yang Dong、Xiang Meng、Xin-Yuan Liu
DOI:10.1002/anie.201804315
日期:2018.6.25
A copper‐catalyzed asymmetric radical oxytrifluoromethylation of alkenyl oxime and Togni's reagent has been successfully developed, thereby providing straightforward access to CF3‐containing isoxazolines bearing α‐tertiary stereocenters with excellent yield and enantioselectivity. The key to success is the rational design of cinchona‐alkaloid‐based sulfonamides as neutral/anionic hybrid ligands to
The iridium-catalyzed asymmetric hydrogenation of 2-aryl allyl phthalimides to afford enantioenriched β-aryl-β-methyl amines is presented. Recently developed Ir-MaxPHOX catalysts are used for this enantioselective transformation. The mild reaction conditions and the feasible removal of the phthalimido group makes this catalytic method easily scalable and of great interest to afford chiral amines. The
Metal-catalyzed cyanoalkylation/cyclization of olefinic 1,3-dicarbonyls with cycloketone oxime esters has been developed under redox-neutral conditions. This protocol provided a straightforward approach to diverse cyanoalkylated 2,3-dihydrofurans via a tandem ring-opening/addition/cyclization process.
A hydroxy group chelation‐assisted stereospecific oxidative cross‐coupling reaction between alkenes was developed under mild reaction conditions. In the presence of palladium catalyst, the alkenes tethered with hydroxy functionality can couple efficiently with electron‐deficient alkenes to form the corresponding multi‐substituted olefin products. The hydroxy group on the substrate could play dual roles