Facile Dephosphonylation of β-Ketophosphonic Acids: Mechanistic Studies
摘要:
We have found that beta-ketophosphonic acids can undergo facile dephosphonylation under fairly mild conditions. The rate of dephosphonylation is dependent on the electronic nature of the substituent on the carbon atom alpha to phosphorus, with electron-withdrawing groups accelerating the process. P-31 NMR studies were used to probe the mechanism for the process.
Aerobic, Transition-Metal-Free, Direct, and Regiospecific Mono-α-arylation of Ketones: Synthesis and Mechanism by DFT Calculations
作者:Qing-Long Xu、Hongyin Gao、Muhammed Yousufuddin、Daniel H. Ess、László Kürti
DOI:10.1021/ja4074563
日期:2013.9.25
We disclose a facile, aerobic, transition-metal-free, direct, and regiospecific mono-α-arylation of ketones to yield aryl benzyl and (cyclo)alkyl benzyl ketones with substitution patterns that are currently inaccessible or challenging to prepare using conventional methods. The transformation is operationally simple, scalable, and environmentally friendly. There is no need for pre-functionalization
我们公开了一种简便、有氧、无过渡金属、直接和区域特异性的酮单-α-芳基化,以产生芳基苄基和(环)烷基苄基酮,其取代模式目前无法使用常规方法制备或难以制备。转型操作简单、可扩展且环保。不需要预官能化(即α-卤化或甲硅烷基烯醇醚形成)或使用专门的芳基化剂(即二芳基碘盐)。DFT 计算表明,原位生成的烯醇化物与硝基芳烃直接形成 CC 键,然后进行区域选择性 O2 介导的 CH 氧化。
Enantioselective Access to Triaryl-2-pyrones with Monoaxial or Contiguous C–C Diaxes via Oxidative NHC Catalysis
materials. This N-heterocyclic carbene catalysis method adopts an atroposelective annulation of 2-aryketones with ynals under oxidative conditions. The annulation includes the construction of one or two axes in a single operation, achieves step economy, and affords axially chiral triaryl-2-pyrones in moderate to good yields, with high to excellent enantioselectivities. DFT calculations of the relative energies
Ascorbic Acid Promoted Oxidative Arylation of Vinyl Arenes to 2-Aryl Acetophenones without Irradiation at Room Temperature under Aerobic Conditions
作者:Biju Majhi、Debasish Kundu、Brindaban C. Ranu
DOI:10.1021/acs.joc.5b00825
日期:2015.8.7
A convenient and general protocol for oxidative arylation of vinyl arenes by aryl radicals generated in situ from arene diazonium fluoroborates promoted by ascorbic acid in air at room temperature has been developed in the absence of any additive and visible light irradiation. A series of diversely substituted 2-aryl acetophenones have been obtained in good yields by this procedure.
Lespagnol; Cheymol; Devulder, Revue Scientifique, 1942, vol. 80, p. 277,278
作者:Lespagnol、Cheymol、Devulder
DOI:——
日期:——
Highly Stereoselective Synthesis of Tetrasubstituted Vinyl Selenides via Rhodium-Catalyzed [1,4]-Acyl Migration of Selenoesters and Diazo Compounds
作者:Xun-Shen Liu、Mingjia Li、Kexin Dong、Shaoting Peng、Lu Liu
DOI:10.1021/acs.orglett.2c00477
日期:2022.3.25
disclose a highly stereoselective Rh(II)-catalyzed 1,4-acyl rearrangement of selenium esters and α-diazo carbonyl compounds, which provides an efficient method for synthesizing tetrasubstituted vinyl selenides. Furthermore, this reaction also offers a synthetic tool for medium and large ring compounds.