Radical Benzylation of Quinones via C–H Abstraction
作者:Jordan D. Galloway、Duy N. Mai、Ryan D. Baxter
DOI:10.1021/acs.joc.9b01004
日期:2019.9.20
Herein we report the development of radical benzylation reactions of quinones using Selectfluor and catalytic Ag(I) initiators. The reaction is believed to proceed via a C–H abstraction mechanism after Ag(I)-mediated reduction of Selectfluor. This reaction occurs under mild conditions and is effective for a variety of quinones and radical precursors bearing primary benzylic carbons. The use of preformed
本文中,我们报道了使用Selectfluor和催化Ag(I)引发剂对醌进行的自由基苄基化反应的发展情况。在Ag(I)介导的Selectfluor还原后,该反应被认为是通过C–H抽象机制进行的。该反应在温和的条件下发生,并且对于各种带有伯苄基碳的醌和自由基前体是有效的。事实证明,使用预制的Ag(4-OMePy)2 NO 3作为催化剂,可通过减少Selectfluor可利用的不需要的降解途径来有效提高反应效率。
Silver-Catalyzed Minisci Reactions Using Selectfluor as a Mild Oxidant
作者:Jordan D. Galloway、Duy N. Mai、Ryan D. Baxter
DOI:10.1021/acs.orglett.7b02706
日期:2017.11.3
A new method for silver-catalyzed Minisci reactions usingSelectfluor as a mild oxidant is reported. Heteroarenes and quinones both participate in radical C–H alkylation and arylation from a variety of carboxylic and boronic acid radical precursors. Several oxidatively sensitive and highly reactive radical species are successful, providing structures that are challenging to access by other means.
Metal-, Photocatalyst-, and Light-Free, Late-Stage C–H Alkylation of Heteroarenes and 1,4-Quinones Using Carboxylic Acids
作者:Daniel R. Sutherland、Marcos Veguillas、Conor L. Oates、Ai-Lan Lee
DOI:10.1021/acs.orglett.8b02988
日期:2018.11.2
Contrary to the accepted convention, this work shows that Minisci-type C–Halkylation does not require any metal, photocatalyst, light, or prefunctionalization of the readily available and inexpensive carboxylic acids to proceed well under mild conditions. These mild conditions can be utilized for late-stage alkylations of complex molecules, including pharmaceutical compounds and light-sensitive compounds
The oxidation of different phenols, viz., phenol, 3-methylphenol, 4-methylphenol, 4-tert-butylphenol, 2-cyclohexylphenol, 2,6-di-tert-butyl-4-methylphenol, and 2,4-dichlorophenol, with chlorine dioxide in acetonitrile was studied spectrophotometrically. The reaction rate is described by a second-order equation w = k[PhOH]· [ClO2]. The rate constants were measured and activation parameters of oxidation were determined in a temperature interval of 10–60°C. A dependence of the reaction rate constant on the phenol structure was found. The oxidation products were identified, and their yields were established.
研究了不同酚类(即苯酚、3-甲基苯酚、4-甲基苯酚、4-叔丁基苯酚、2-环己基苯酚、2,6-二叔丁基-4-甲基苯酚和2,4-二氯苯酚)在乙腈中与二氧化氯的氧化反应,通过分光光度法进行研究。反应速率由二级方程 w = k[PhOH]·[ClO2] 描述。在10-60°C的温度区间内测定了速率常数并确定了氧化反应的活化参数。发现反应速率常数与酚的结构有关。鉴定了氧化产物并确定了其产率。
Copper catalyzed direct alkenylation of simple alkanes with styrenes
作者:Yefeng Zhu、Yunyang Wei
DOI:10.1039/c4sc00093e
日期:——
A novel Cu-catalyzed direct alkenylation of simple alkanes with styrenes was described. In the presence of a catalytic amount of Cu(OTf)2, a diverse range of alkenes undergo coupling with cycloalkanes to produce (E)-alkyl alkenes. This transformation is proposed to proceed via a radical process.