345-92-6Relevant articles and documents
Zwitterion-induced organic-metal hybrid catalysis in aerobic oxidation
Hu, Rong-Bin,Lam, Ying-Pong,Ng, Wing-Hin,Wong, Chun-Yuen,Yeung, Ying-Yeung
, p. 3498 - 3506 (2021/04/07)
In many metal catalyses, the traditional strategy of removing chloride ions is to add silver salts via anion exchange to obtain highly active catalysts. Herein, we reported an alternative strategy of removing chloride anions from ruthenium trichloride using an organic [P+-N-] zwitterionic compound via multiple hydrogen bond interactions. The resultant organic-metal hybrid catalytic system has successfully been applied to the aerobic oxidation of alcohols, tetrahydroquinolines, and indolines under mild conditions. The performance of zwitterion is far superior to that of many other common Lewis bases or Br?nsted bases. Mechanistic studies revealed that the zwitterion triggers the dissociation of chloride from ruthenium trichloride via nonclassical hydrogen bond interaction. Preliminary studies show that the zwitterion is applicable to catalytic transfer semi-hydrogenation.
Preparation method 4,4 ' -difluorobenzophenone and intermediate thereof
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, (2021/09/01)
The invention discloses 4-4' -difluorobenzophenone and a preparation method of an intermediate thereof. The preparation method of 4, 4 '- difluorobenzophenone comprises the following steps: S1: 4 - chlorobenzyl chloride and chlorobenzene react under first catalyst to obtain 4, 4' -dichlorophenylmethane. The first catalyst is Lewis acid and/or a molecular sieve with Lewis acid center. S2: The 4, 4 '-dichlorophenylmethane and oxidant are subjected to an oxidation reaction under the action second catalyst to obtain 4, 4' -dichlorobenzophenone. S3: The 4, 4' -dichlorobenzophenone and the alkali metal fluoride are subjected to a halogenation reaction to obtain the invention. The 4' - difluorobenzophenone and the intermediate thereof disclosed by the invention are high in selectivity, high in yield, low in raw material cost, mild in process condition, high in safety and wide in industrial prospect.
Decatungstate-mediated solar photooxidative cleavage of CC bonds using air as an oxidant in water
Du, Dongdong,Luo, Junfei,Shi, Sanshan,Xie, Pan,Xue, Cheng
, p. 5936 - 5943 (2021/08/23)
With the increasing attention for green chemistry and sustainable development, there has been much interest in searching for greener methods and sources in organic synthesis. However, toxic additives or solvents are inevitably involved in most organic transformations. Herein, we first report the combination of direct utilization of solar energy, air as the oxidant and water as the solvent for the selective cleavage of CC double bonds in aryl olefins. Various α-methyl styrenes, diaryl alkenes as well as terminal styrenes are well tolerated in this green and sustainable strategy and furnished the desired carbonyl products in satisfactory yields. Like heterogeneous catalysis, this homogeneous catalytic system could also be reused and it retains good activity even after repeating three times. Mechanism investigations indicated that both O2- and 1O2 were involved in the reaction. Based on these results, two possible mechanisms, including the electron transfer pathway and the energy transfer pathway, were proposed.