The visible-light-induced acylation/cyclization of alkynoates with acyl oximes for the construction of 3-acylcoumarins
作者:Quan Zhou、Fang-Ting Xiong、Pu Chen、Bi-Quan Xiong、Ke-Wen Tang、Yu Liu
DOI:10.1039/d1ob01568k
日期:——
by the visible-light-induced acylation/cyclization of alkynoates with various acyl oximecompounds in acetonitrile. The difunctionalization of carbon–carbon triple bonds precedes the generation of iminyl radicals, which is followed by the formation of acyl radicals. The acyl radicals then attack the carbon–carbon triple bonds, followed by 5-exo-trig cyclization and 1,2-ester migration. This strategy
Comparative nucleophilic reactivities in carboxylate, phosphinate, and thiophosphate esters cleavage
作者:Kallol K. Ghosh、Sunita Bal、Sancheeta Kolay、Ashish Shrivastava
DOI:10.1002/poc.1370
日期:2008.6
Nucleophilic substitutionreaction of p-nitrophenyl acetate (PNPA), p-nitrophenyldiphenyl phosphinate, and pesticide parathion with different α-nucleophiles [I] have been studied at 27 °C in different pH in the presence of a novel cationic surfactant. The kineticstudy was performed spectrophotometrically under pseudo-first order conditions with the α-nucleophile in excess. The pKa of nucleophiles
Visible-Light Photoredox-Catalyzed Dicarbofunctionalization of Styrenes with Oxime Esters and CO<sub>2</sub>: Multicomponent Reactions toward Cyanocarboxylic Acids and γ-Keto Acids
作者:Junxue Bai、Miao Li、Cong Zhou、Yu Sha、Jiang Cheng、Jianwei Sun、Song Sun
DOI:10.1021/acs.orglett.1c03938
日期:2021.12.17
photoredox-catalyzed dicarbofunctionalization of styrenes with oximeesters and CO2 has been achieved. Notably, a series of four-, five-, or six-membered cyclic ketone oximes worked well to furnish a wide range of ε-, ζ-, and η-cyanocarboxylic acids in good yields. Furthermore, a series of γ-keto acids also could be obtained by employing acyclic ketone oximeesters as the carbonyl radical precursor. It provides convergent
已经实现了苯乙烯与肟酯和 CO 2的光氧化还原催化双碳官能化。值得注意的是,一系列四元、五元或六元环酮肟可以很好地以良好的产率提供各种 ε-、ζ- 和 η-氰基羧酸。此外,以无环酮肟酯为羰基自由基前驱体,还可以得到一系列γ-酮酸。它提供了对多种生物学上重要的氰基羧酸和 γ-酮酸的聚合访问。
Dual Photoredox/Palladium-Catalyzed C–H Acylation of 2-Arylpyridines with Oxime Esters
unprecedented dual photoredox/palladium-catalyzed iminyl-radical-mediated C–C bond cleavage and directed ortho C–H acylation of 2-arylpyridines by using oxime esters is described. Oxime esters can serve as efficient acyl sources through formation of the corresponding acylradicals by photoredox-catalyzed iminyl-radical-mediated C–C bond cleavage. This redox-neutral protocol features excellent regioselectivity
Solvent Effect on the α-Effect: Ground-State versus Transition-State Effects; a Combined Calorimetric and Kinetic Investigation
作者:Ik-Hwan Um、So-Jeong Hwang、Erwin Buncel
DOI:10.1021/jo051823f
日期:2006.2.1
βnuc is an important predictor of the magnitude of the α-effect. The bell-shaped α-effect profile found in the present system is attributed to the differential change in the sensitivity of the medium effect on the Ox- and p-ClPhO- systems but not due to a change in the reaction mechanism or to a drastic change in the basicity of the two nucleophiles on addition of DMSO to the medium. Through application