General Paradigm in Photoredox Nickel‐Catalyzed Cross‐Coupling Allows for Light‐Free Access to Reactivity
作者:Rui Sun、Yangzhong Qin、Daniel G. Nocera
DOI:10.1002/anie.201916398
日期:2020.6.8
Self‐sustained NiI/III cycles are established as a potentially generalparadigm in photoredox Ni‐catalyzed carbon–heteroatom cross‐coupling reactions through a strategy that allows us to recapitulate photoredox‐like reactivity in the absence of light across a wide range of substrates in the amination, etherification, and esterification of aryl bromides, the latter of which has remained, hitherto, elusive
自我维持的Ni I / III循环被确立为光氧化还原Ni催化的碳-杂原子交叉偶联反应中的潜在一般范式,其策略是使我们能够在没有光的情况下在各种各样的底物上重现类似光氧化还原的反应性。在芳基溴化物的胺化,醚化和酯化反应中,迄今为止,后者在热镍催化下仍然难以捉摸。此外,在没有光照的情况下酯化的可及性尤其显着,因为先前在光氧化还原条件下对该转化进行的机理研究一致地调用了能量转移介导的途径。
Nickel-Catalyzed Cross-Coupling of Aryl Redoxactive Esters with Aryl Zinc Reagents
作者:Bo-Hao Shih、R. Sidick Basha、Chin Fa Lee
DOI:10.1021/acscatal.9b02913
日期:2019.10.4
reaction conducted using a redox active ester with aryl zinc reagent was developed. This method demonstrates a new disconnection approach for formation of arylaryl esters. In the one-pot sequential process, the readily available aryl carboxylic acids can be converted into functionalized arylaryl esters and heteroaryl esters. This protocol is amenable to the gram-scale synthesis. The present method
The first example of a palladium-catalyzed aerobic oxidative coupling of acyl chlorides with arylboronic acids has been developed, leading to a wide range of aryl benzoates in good to excellent yields. This catalytic system shows broad functional group tolerance. Preliminary mechanistic experiments using deuterium labeling showed that the oxygen atom was derived from dioxygen.
Conversion of esters to thioesters under mild conditions
作者:Yijun Shi、Xuejing Liu、Han Cao、Fusheng Bie、Ying Han、Peng Yan、Roman Szostak、Michal Szostak、Chengwei Liu
DOI:10.1039/d1ob00187f
日期:——
We report conversion of esters to thioesters via selective C–O bond cleavage/weak C–S bond formation under transition-metal-free conditions. The method is notable for a general and practical transition-metal-free system, broad substrate scope and excellent functional group tolerance. The strategy was successfully deployed in late-stage thioesterification, site-selective cross-coupling/thioesterifi
Palladium-Catalyzed Aerobic Oxidative Coupling of Amides with Arylboronic Acids by Cooperative Catalysis
作者:Yue Li、Hongxiang Wu、Zhuo Zeng
DOI:10.1002/ejoc.201900531
日期:2019.7.23
A new conceptual method, the first fluoride and palladium co‐catalyzed conversion of amide to ester through an aerobic oxidative coupling pathway is reported. This work demonstrates the synergistic combination of fluoride and palladium catalysis as a new concept to activate inert amide N–C bonds, which may facilitate the growing utilization of amides as synthons in a variety of transformations.