4044-60-4Relevant articles and documents
Friedel-crafts acylation of p-Xylene over sulfonated zirconium terephthalates
Chung, Young-Min,Kim, Hee-Young,Ahn, Wha-Seung
, p. 817 - 824 (2014)
In this study, a sulfonated Zr-terephthalate metal-organic framework (MOF) (UiO-66-SO3H) was prepared using two different methods: post-synthetic grafting onto the Zr open metal sites and direct solvothermal method using monosodium 2-sulfoterephthalate. Their catalytic activities for the acid-catalyzed Friedel- Crafts acylation of p-xylene with benzoyl chloride were compared. The physicochemical properties and catalytic performance of the functionalized MOF structure was found to be strongly dependent on the synthesis scheme. UiO-66-SO3H prepared by a direct solvothermal route exhibited excellent catalytic activity and stability compared to that prepared by post-synthetic grafting. Springer Science+Business Media New York 2014.
High activity of Ga-containing nanosponge MTW zeolites in acylation of p-xylene
Zhang, Jin,Vesely, Ond?ej,Shamzhy, Mariya V.,Opanasenko, Maksym,?ejka, Ji?i
, p. 110 - 115 (2020)
Aluminosilicate and gallosilicate MTW zeolites were prepared in the bulk and nanosponge form by direct hydrothermal synthesis. Designed materials were tested in acylation of p-xylene with benzoyl chloride and compared with large pore zeolite *BEA and medium pore zeolite MFI. Nanosponge MTW exhibited generally better performance than bulk MTW zeolites due to higher accessibility of the catalyst′s active sites in nanosponge zeolite. Selective transformation of benzoyl chloride towards target 2,5-dimethylbenzophenone was achievable over nanosponge MTW zeolites. The gallosilicate nanosponge MTW exhibited significantly higher conversion (61%) of benzoyl chloride than its aluminosilicate counterpart (27%) with the same concentration of Br?nsted acid sites (0.04 mmol/g). This result is clearly caused by the suitable strength of acid centres in Ga-MTW, which enables the sufficient activation of BzCl molecules as well as efficient desorption of formed polar products. Additionally, the gallosilicate MTW outperformed both conventional zeolites *BEA and MFI used as reference materials.
A palladium-catalyzed C-H functionalization route to ketones: Via the oxidative coupling of arenes with carbon monoxide
Arndtsen, Bruce A.,Kinney, R. Garrison,Levesque, Taleah M.
, p. 3104 - 3109 (2020/03/27)
We describe the development of a new palladium-catalyzed method to generate ketones via the oxidative coupling of two arenes and CO. This transformation is catalyzed by simple palladium salts, and is postulated to proceed via the conversion of arenes into high energy aroyl triflate electrophiles. Exploiting the latter can also allow the synthesis of unsymmetrical ketones from two different arenes.
Stereochemical outcomes of C–F activation reactions of benzyl fluoride
Champagne, Pier Alexandre,Desroches, Justine,Keddie, Neil S.,O'Hagan, David,Paquin, Jean-Fran?ois
supporting information, p. 106 - 113 (2020/05/06)
In recent years, the highly polar C–F bond has been utilised in activation chemistry despite its low reactivity to traditional nucleophiles, when compared to other C–X halogen bonds. Paquin's group has reported extensive studies on the C–F activation of benzylic fluorides for nucleophilic substitutions and Friedel–Crafts reactions, using a range of hydrogen bond donors such as water, triols or hexafluoroisopropanol (HFIP) as the activators. This study examines the stereointegrity of the C–F activation reaction through the use of an enantiopure isotopomer of benzyl fluoride to identify whether the reaction conditions favour a dissociative (SN1) or associative (SN2) pathway. [2H]-Isotopomer ratios in the reactions were assayed using the Courtieu 2H NMR method in a chiral liquid crystal (poly-γ-benzyl-L-glutamate) matrix and demonstrated that both associative and dissociative pathways operate to varying degrees, according to the nature of the nucleophile and the hydrogen bond donor.
