Solid‐State Radical C−H Trifluoromethylation Reactions Using Ball Milling and Piezoelectric Materials
作者:Yadong Pang、Joo Won Lee、Koji Kubota、Hajime Ito
DOI:10.1002/anie.202009844
日期:2020.12.7
The application of piezoelectricity for the generation of trifluoromethyl (CF3) radicals is reported together with the development of a method for the mechanochemical C−H trifluoromethylation of aromatic compounds. As compared to conventional solution‐based approaches, this mechanoredox C−H trifluoromethylation enables cleaner and more sustainable access to a wide range of trifluoromethylated N‐heterocycles
Thieme Journal Awardees - Where Are They Now? On Cobalt-Catalyzed Biaryl Coupling Reactions
作者:Axel Jacobi von Wangelin、Matthias Mayer、Waldemar Czaplik
DOI:10.1055/s-0029-1218013
日期:2009.11
An operationally simple biaryl coupling reaction has been developed. The underlying domino process involves in situGrignard formation from aryl bromides and subsequent homocoupling with catalytic CoCl 2 and I bar synthetic air as terminal oxidant.
已开发出操作简单的联芳基偶联反应。潜在的多米诺骨牌过程涉及由芳基溴化物原位形成格氏,随后与催化 CoCl 2 和 I bar 合成空气作为末端氧化剂均偶联。
Aerobic homocoupling of arylboronic acids catalysed by copper terephthalate metal–organic frameworks
Copper terephthalate MOF is utilised as an environmentally benign, efficient and reusable heterogeneous catalyst to effect the aerobic homocoupling of arylboronic acids yielding the corresponding symmetrical biphenyls under mild reaction conditions. This method tolerates various substituents present in arylboronic acids such as halogens, cyano and nitro groups. The catalytic performance has been compared with that of other copper based MOFs namely MOF-101, [Cu(pdc)2]NH2Me2, [Cu2(ndc)2ted]n and [Cu(H2L)]n as well as with other copper salt catalysts. Sheldon test confirmed the heterogeneity of the catalyst, which can be reused under optimized conditions with only a minor loss in its activity. A mechanism for the homocoupling reaction is also proposed. The simplicity of catalyst preparation, its stability, substrate selectivity, easy recovery and regeneration designate possible utilization of this catalytic system in a multitude of catalytic reactions and industrial processes.
Ligand- and Base-Free Access to Diverse Biaryls by the Reductive Coupling of Diaryliodonium Salts
作者:V. Arun、P. O. Venkataramana Reddy、Meenakshi Pilania、Dalip Kumar
DOI:10.1002/ejoc.201600242
日期:2016.4
Pd-catalyzed protocol to access a wide range of symmetrical and unsymmetrical biaryls from stable diaryliodonium salts was developed. The reaction involved the use of an effective and recyclable Pd/polyethylene glycol-400 catalyst system to harness the aryl moieties of two diaryliodonium salts; the ensuing biaryls may be utilized to synthesize an array of useful compounds, including 5-aryluracils, carbazoles