Synthetically and biologically interesting N-acyl quinone imine ketals and N-acyl quinol imine ethers from anodic oxidation of anilides
作者:Chung Pin Chen、Chun Tzer Chou、John S. Swenton
DOI:10.1021/ja00237a077
日期:1987.2
Oxydation sur une electrode de platine dans le methanol-perchlorate de lithium de N-[methoxy-4 phenyl]-benzamide, -acetamide et d'(acylamino-2 methoxy-5) benzeneacetate d'ethyle
Addition of elemental selenium to phosphonate carbanions- - a key step in the synthesis of vinylphosphonates. A new synthetic approach to 1,4-dicarbonyl systems.
A convenient synthesis of vinylphosphonates which involves addition of elemental selenium to phosphonate carbanions followed by alkylation and selenoxide elimination is described. A general approach to 1,4-dicarbonyl systems based on diethyl α-methylthiovinylphosphonate is also reported.
Studies on fluoroalkylation and fluoroalkoxylation. Part 10. Electron-transfer induced reactions of perfluoroalkyl iodides and the dialkyl malonate anion and β-fragmentation of the halotetrafluoroethyl radical
作者:Qing-Yun Chen、Zai-Ming Qiu
DOI:10.1016/s0022-1139(00)81433-5
日期:1986.4
malonic ester anion () in DMF to give (), 1-hydroperfluoroalkane () and dimer of the anion (). The reaction is accelerated by UV irradiation and partly suppressed by p-DNB. Diallyl ether (DAE) can trap the radical intermediates to afford five-membered ring products. Interestingly, in the case of ( X = Cl, I ) the same reaction mainly yielded tetrafluoroethylene and instead of and . The radical intermediate
Rhodium-catalysed chemo- and regio-selective [3 + 2+2] cycloadditions of bis(methylenecyclopropanes) and alkynes: Synthesis of spirocyclic 5–7 condensed cycloheptenes
Abstract Rhodium-catalyzed intermolecular [3 + 2+2] cycloaddition reactions of bis(methylenecyclopropanes) with different alkynes are described. The rhodium-catalyzed [3 + 2+2] cycloadditions resulted in the formation of functionalized 5–7–3 spirocyclic carbocycles in moderate yields with excellent regio- and chemo-selectivity. GRAPHICAL ABSTRACT
Measurement of pK a values for phosphonium salts via the kinetics of proton transfer to an electrogenerated base
作者:Sim Ling-Chung、Keith D. Sales、James H. P. Utley
DOI:10.1039/c39900000662
日期:——
pKa values have for the first time been measured for common phosphonium ions, including butyl-, allyl-, prop-2-ynyl- and benzyl-triphenylphosphonium, by comparison through a linear Brønsted plot of their rates of protontransfer to an electrogeneratedbase with those involving carbon acids of known acidity.
通过对质子转移至电生成速率的线性布朗斯台德曲线进行比较,首次测量了常见的离子(包括丁基,烯丙基,丙-2-炔基和苄基三苯基phosph)的p K a值含已知酸度的碳酸的碱。