32446-66-5Relevant articles and documents
ε-Caprolactone manufacture via efficient coupling Baeyer-Villiger oxidation with aerobic oxidation of alcohols
Du, Renfeng,Li, Haoran,Wang, Yongtao,Yao, Jia,Yuan, Haoran,Zhao, Chenxuan
, (2020/04/27)
To avoid the use of peracids oxidant or highly concentrated hydrogen peroxide which is potentially hazardous and explosive, herein, a new route to ε-caprolactone was developed in which molecule oxygen was employed as the terminal oxidant. The commercial available N-hydroxyphthalimide and ammonium cerium nitrate were used as the key catalysts for the increased yield of ε-caprolactone. For instance, the selectivity of ε-caprolactone was obtained 92 % with 85 % conversion of cyclohexanone which was comparable to the strategies using highly concentrated hydrogen peroxide. The sacrificed alcohols were transformed into corresponding ketones which were also valuable chemicals. Furthermore, the efficiency of the alcohols was achieved to unprecedented 52 %. The Baeyer-Villiger oxidation of various other cycloalkanones was also examined. The substituent group effect on the efficiency of sacrificed alcohols was investigated in which weak electron-donating substituent induced nearly quantitative yield of ε-caprolactone. The reaction mechanism was studied with the help of electron paramagnetic resonance which indicated the existence of a radical pathway.
Method for preparing symmetric diarylketone through catalytic oxidative carbonylation
-
Paragraph 0023; 0024; 0025; 0026; 0030, (2019/03/08)
The invention discloses a method for preparing symmetric diarylketone of a formula (I) as shown in the description. The method comprises the following steps: mixing arylboronic acid (II) (Ar-B(OH)2 (II)), a palladium catalyst, a promoter and an organic solvent in a reactor, introducing air and CO having a volume ratio of (7-19):1, reacting under the conditions of a pressure of 1-6 atm and a temperature of 30-80 DEG C for 8-16 hours, and performing after-treatment on the reaction solution, thereby obtaining the product symmetric diarylketone. According to the method disclosed by the invention,the air directly serves as an oxidizing agent to replace the O2 to be applied to oxidative carbonylation of the arylboronic acid, and the ratio of the air to CO is beyond an explosion limit. Therefore, the catalytic system is safe and economic. The palladium catalyst is small in dosage and simple in separation and can be recycled for several times. The method disclosed by the invention is mild inreaction condition, excellent in substrate suitability and high in yield.
