Redox‐Neutral TEMPO Catalysis: Direct Radical (Hetero)Aryl C−H Di‐ and Trifluoromethoxylation
作者:Johnny W. Lee、Sanghyun Lim、Daniel N. Maienshein、Peng Liu、Ming‐Yu Ngai
DOI:10.1002/anie.202009490
日期:2020.11.23
Applications of TEMPO. catalysis for the development of redox‐neutral transformations are rare. Reported here is the first TEMPO.‐catalyzed, redox‐neutralC−Hdi‐ and trifluoromethoxylation of (hetero)arenes. The reaction exhibits a broad substrate scope, has high functional‐group tolerance, and can be employed for the late‐stage functionalization of complex druglike molecules. Kinetic measurements
TEMPO 的应用。氧化还原中性转化发展的催化作用很少见。这里报道的是第一个TEMPO 。(杂)芳烃的催化氧化还原中性 C−H 二氟甲氧基化和三氟甲氧基化。该反应表现出广泛的底物范围,具有较高的官能团耐受性,可用于复杂药物分子的后期功能化。动力学测量、催化中间体的分离和重新研究、UV/Vis 研究和 DFT 计算支持了所提出的氧化 TEMPO 。/TEMPO +氧化还原催化循环。机理研究还表明Li 2 CO 3在防止催化剂失活方面发挥着重要作用。这些发现将为通过氧化还原中性 TEMPO 设计和开发新型反应提供新的见解。催化。
Redox‐Active Reagents for Photocatalytic Generation of the OCF
<sub>3</sub>
Radical and (Hetero)Aryl C−H Trifluoromethoxylation
作者:Weijia Zheng、Johnny W. Lee、Cristian A. Morales‐Rivera、Peng Liu、Ming‐Yu Ngai
DOI:10.1002/anie.201808495
日期:2018.10.15
importantly, the reagent allows catalytic, intermolecular C−H trifluoromethoxylation of a broad array of (hetero)arenes and biorelevant compounds. Experimental and computational studies suggest single electron transfer (SET) from excited photoredox catalysts to 1 resulting in exclusive liberation of the OCF3 radical. Addition of this radical to (hetero)arenes gives trifluoromethoxylated cyclohexadienyl radicals
Visible-Light-Mediated Late-Stage Sulfonylation of Boronic Acids via N–S Bond Activation of Sulfonamides
作者:Jingsong Zhen、Xian Du、Xiaohong Xu、Yihui Li、Han Yuan、Dejing Xu、Can Xue、Yong Luo
DOI:10.1021/acscatal.1c05669
日期:2022.2.4
late-stage arylation of N–S bonds in sulfonamides has been developed with using readily available imines as sulfonyl radical source. Diverse complex sulfones could be synthesized by prefunctionalizaiton and subsequent N–S bond arylation, demonstrating the advantages of using sulfonamides as sulfonylation reagents. Additionally, the mechanism research revealed that probably both EDA complex chemistry and photoredox
Photocatalytic trifluoromethoxylation of arenes and heteroarenes in continuous-flow
作者:Alexander V Nyuchev、Ting Wan、Borja Cendón、Carlo Sambiagio、Job J C Struijs、Michelle Ho、Moisés Gulías、Ying Wang、Timothy Noël
DOI:10.3762/bjoc.16.111
日期:——
of arenes and heteroarenes undercontinuous-flowconditions is described. Application of continuous-flowmicroreactor technology allowed to reduce the residence time up to 16 times in comparison to the batch procedure, while achieving similar or higher yields. In addition, the use of inorganic bases was demonstrated to increase the reaction yield under batch conditions.
Electrochemical Trifluoromethoxylation of (Hetero)aromatics with a Trifluoromethyl Source and Oxygen
作者:Yao Ouyang、Xiu‐Hua Xu、Feng‐Ling Qing
DOI:10.1002/anie.202114048
日期:2022.1.17
A conceptually new trifluoromethoxylation reaction through the combination of readily available trifluoromethylating reagent and oxygen under electrochemical conditions was developed. The synthetic utility of this new protocol is illustrated by the C−H trifluoromethoxylation of (hetero)arenes and biorelevant molecules.