The arylation of pyrazole and derivatives can be achieved by coupling arenediazonium species (formed in situ fromanilines) by using a catalytic system that employs low‐toxicity and inexpensive copper metal under very mild and ligand‐free conditions (T=20 °C). From other nitrogenheterocycles, the presence of an additive (NBu4I) significantly improves the efficiency of the catalytic system. These results
Mechanochemical Ruthenium-Catalyzed Hydroarylations of Alkynes under Ball-Milling Conditions
作者:Hanchao Cheng、José G. Hernández、Carsten Bolm
DOI:10.1021/acs.orglett.7b02973
日期:2017.12.1
mechanochemical ruthenium-catalyzed hydroarylations of alkynes with acetanilides lead to trisubstituted alkenes. Only catalytic amounts of pivalic acid or copper acetate are required, and without the need for external heating, the reaction times are shorter than those of their solution-based counterpart. Mechanochemical oxidative annulations through palladium-catalyzed intramolecular amination convert the products
Ruthenium‐Catalyzed Remote Difunctionalization of Nonactivated Alkenes for Double <i>meta</i>‐C(sp<sup>2</sup>)−H/C‐6(sp<sup>3</sup>)−H Functionalization
The ruthenium-catalyzed remote-difunctionalization of nonactivated alkenes for double meta-C(sp2)−H/C-6(sp3)−H transformations was achieved by metalla-hydrogen atom transfer (MHAT) and σ-activation, featuring excellent site- and regio-selectivity, along with ample scope.
Intermolecular Aryl C−H Amination through Sequential Iron and Copper Catalysis
作者:Mohamed A. B. Mostafa、Ewen D. D. Calder、Daugirdas T. Racys、Andrew Sutherland
DOI:10.1002/chem.201605671
日期:2017.1.23
regioselective method for para-amination of activated arenes has been developed through a combination of iron and copper catalysis. A diverse range of products were obtained from an operationally simple one-pot, two-step procedure involving bromination of the aryl substrate with the powerful Lewis acid iron(III) triflimide, followed by a copper(I)-catalysed N-arylation reaction. This two-step dehydrogenative
The first electrochemical transition-metal-catalyzed meta-C−H functionalization has been accomplished, affording the positionally selective bromination product in an undivided cell by the catalysis of readily available RuCl3⋅3 H2O with aqueous HBr as the brominating agent.
第一个电化学过渡金属催化的间位-C−H 官能化已经完成,通过容易获得的 RuCl 3 ⋅3 H 2 O 和水性 HBr 作为溴化剂的催化作用,在未分割的电池中提供了位置选择性的溴化产物。