Dalton Trans. 2018 Jul 24;47(29):9608-9616. doi: 10.1039/c8dt01090k.

Silica-supported silver nanoparticles as an efficient catalyst for aromatic C-H alkylation and fluoroalkylation.

Dalton transactions (Cambridge, England : 2003)

Mikhail N Khrizanforov, Svetlana V Fedorenko, Asiya R Mustafina, Kirill V Kholin, Irek R Nizameev, Sofia O Strekalova, Valeriya V Grinenko, Tatiana V Gryaznova, Rustem R Zairov, Raffaello Mazzaro, Vittorio Morandi, Alberto Vomiero, Yulia H Budnikova

PMID: 29855006 DOI: 10.1039/c8dt01090k

Abstract

The efficient catalysis of oxidative alkylation and fluoroalkylation of aromatic C-H bonds is of paramount importance in the pharmaceutical and agrochemical industries, and requires the development of convenient Ag0-based nano-architectures with high catalytic activity and recyclability. We prepared Ag-doped silica nanoparticles (Ag0/+@SiO2) with a specific nano-architecture, where ultra-small sized silver cores are immersed in silica spheres, 40 nm in size. The nano-architecture provides an efficient electrochemical oxidation of Ag+@SiO2 without any external oxidant. In turn, Ag+@SiO2 5 mol% results in 100% conversion of arenes into their alkylated and fluoroalkylated derivatives in a single step at room temperature under nanoheterogeneous electrochemical conditions. Negligible oxidative leaching of silver from Ag0/+@SiO2 is recorded during the catalytic coupling of arenes with acetic, difluoroacetic and trifluoroacetic acids, which enables the good recyclability of the catalytic function of the Ag0/+@SiO2 nanostructure. The catalyst can be easily separated from the reaction mixture and reused a minimum of five times upon electrochemical regeneration. The use of the developed Ag0@SiO2 nano-architecture as a heterogeneous catalyst facilitates aromatic C-H bond substitution by alkyl and fluoroalkyl groups, which are privileged structural motifs in pharmaceuticals and agrochemicals.

Publication Types

• Journal Article