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。
Quinone C–H Alkylations via Oxidative Radical Processes
作者:Ryan Baxter、Akil Hamsath、Jordan Galloway
DOI:10.1055/s-0037-1610005
日期:2018.8
context of selecting optimum radical precursors and initiators depending on quinone identity and functional groups present. A brief survey of radical additions to quinones is reported. Carboxylic acids, aldehydes, and unprotected amino acids are compared as alkyl radical precursors for the mono- or bis- C–H alkylation of several quinones. Two methods for radical initiation are discussed comparing inorganic
Copper‐Catalyzed Oxidative C(<i>sp</i><sup>3</sup>)−H/N−H Cross‐Coupling of Hydrocarbons with P(O)−NH Compounds: the Accelerating Effect Induced by Carboxylic Acid Coproduct
An chelation‐assisted oxidative C(sp3)−H/N−H cross coupling of hydrocarbons with P(O)−NH compounds using copper acetate as catalyst is described. The results of kinetic experiments, mechanistic studies and DFT calculations demonstrate the importance of acetic acid coproduct as an additive for promoting the formation of intermediate bis((diphenylphosphoryl)(quinolin‐8‐yl)amino)copper (6), and consequently
An efficient metal-free method for the synthesis of organophosphorus compounds via oxidative cross dehydrogenative coupling of benzylicC(sp3)–H bonds in methylarenes with P(O)–OH compounds catalysed by cetyltrimethyl ammonium bromide (CTAB) is reported. Various methylarenes and P(O)–OH compounds are tolerated in the reaction with moderate to good yields. Compared to previous studies, the present study
Ruthenium-Catalyzed Oxidative Dearomatization of Phenols to 4-(tert-Butylperoxy)cyclohexadienones: Synthesis of 2-Substituted Quinones from p-Substituted Phenols
The ruthenium-catalyzedoxidation of phenols with tert-butylhydroperoxide efficiently gives the corresponding 4-(tert-butylperoxy)cyclohexadienones. The oxidation proceeds selectively because of ruthenium's ability for rapid single-electron transfer. This biomimetic oxidation reaction is highly useful to obtain the metabolic compounds desired for confirming the safety of medicines and related compounds