Efficient and selective hydrogenation of C–O bonds with a simple sodium formate catalyzed by nickel
作者:Xiaoxiang Xi、Tieqiao Chen、Ji-Shu Zhang、Li-Biao Han
DOI:10.1039/c7cc08709h
日期:——
A Ni-catalyzed hydrogenation of C–O compounds with sodium formate is developed. Various esters, i.e. aryl, alkenyl, benzyl pivalates, and even the arylethers, were efficiently reduced with a loading of nickel catalysts down to 0.5 mol%. Reactive functional groups such as C–C double bonds, carbonyl, CN, MeS and halogen groups are tolerable. This reaction can be used for the modification of complex
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。
Rhodium-Catalyzed Deoxygenation and Borylation of Ketones: A Combined Experimental and Theoretical Investigation
The rhodium-catalyzed deoxygenation and borylation of ketones with B2pin2 have been developed, leading to efficient formation of alkenes, vinylboronates, and vinyldiboronates. These reactions feature mild reaction conditions, a broad substrate scope, and excellent functional-group compatibility. Mechanistic studies support that the ketones initially undergo a Rh-catalyzed deoxygenation to give alkenes
Copper-Mediated Functionalization of Aryl Trifluoroborates
作者:Melanie Sanford、Sydonie Schimler
DOI:10.1055/s-0035-1562529
日期:——
trifluoroborates with tetrabutylammonium or alkali metal salts to form C–O, C–N, and C–halogen bonds. The reactions proceed under mild conditions (often room temperature over 16 hours) with carboxylate, halide, and azide salts, all nucleophiles that have been underrepresented in the copper cross-coupling literature. Preliminary results show that coppersalts bearing weakly coordinating X-type ligands
本文描述了 Cu(OTf)2 介导的芳基和杂芳基三氟硼酸盐与四丁基铵或碱金属盐的偶联,形成 C-O、C-N 和 C-卤素键。反应在温和条件下进行(通常在室温下超过 16 小时),使用羧酸盐、卤化物和叠氮化物,所有亲核试剂在铜交叉偶联文献中都没有得到充分体现。初步结果表明,带有弱配位 X 型配体的铜盐对于使这些转化在温和条件下进行是必不可少的。
Nickel‐Mediated Trifluoromethylation of Phenol Derivatives by Aryl C−O Bond Activation
作者:Wei‐Qiang Hu、Shen Pan、Xiu‐Hua Xu、David A. Vicic、Feng‐Ling Qing
DOI:10.1002/anie.202004116
日期:2020.9.7
trifluoromethylation reactions. Tremendous efforts have focused on copper‐ and palladium‐mediated/catalyzed trifluoromethylation of aryl halides. In contrast, no general method exists for the conversion of widely available inert electrophiles, such as phenol derivatives, into the corresponding trifluoromethylated arenes. Reported herein is a practical nickel‐mediated trifluoromethylation of phenol derivatives with readily