# Synthesis of vinyl esters of aromatic carboxylic acids in the presence of Zn/SiOC, ZnO/SiOC, and Ni/SiOC catalytic systems

## TL;DR

This paper reports a new method for making vinyl esters of aromatic carboxylic acids using specific heterogeneous catalysts, achieving high yields under controlled conditions.

## Contribution

The first use of Zn/SiOC, ZnO/SiOC, and Ni/SiOC catalytic systems for vinylation of aromatic acids under heterogeneous conditions.

## Key findings

- High yields of vinyl esters (65-91%) were achieved using Zn/SiOC-50 at 10 mol% loading in DMF at 150°C for 12 hours.
- The vinylation reaction was effective for both monocarboxylic and dicarboxylic aromatic acids.
- Structural confirmation of the products was done using FTIR, 1H NMR, 13C NMR, and MS analyses.

## Abstract

In this work, various aromatic monocarboxylic and dicarboxylic acids were subjected for the first time to a vinylation reaction with acetylene under heterogeneous catalytic conditions using catalytic systems based on silicon oxycarbide supported on silicon carbide (SiC): zinc silicon oxycarbide (Zn/SiOC), zinc oxide silicon oxycarbide (ZnO/SiOC), and nickel silicon oxycarbide (Ni/SiOC). The influence of the nature of the starting materials, temperature, reaction duration, solvent, and catalyst type on the yield of vinyl esters was investigated. The vinylation reaction of aromatic carboxylic acids with acetylene was carried out at 1:2 molar ratio, using a Zn/SiOC-50 catalytic system at a loading of 10 mol% relative to the initial aromatic carboxylic acid, in a N,N-dimethylformamide (DMF) solution at 150 C for 12 h, resulting in high yields of vinyl esters. Under these heterogeneous catalytic conditions, the vinylation reaction afforded the following vinyl esters: benzoic acid (80%), 4-methylbenzoic acid (77%), 4-methoxybenzoic acid (70%), 4-fluorobenzoic acid (83%), 4-tert-butylbenzoic acid (65%), 4-chlorobenzoic acid (85%), divinyl esters of ortho-phthalic acid (88%), and terephthalic acid (91%). The structures of the synthesized vinyl esters were confirmed by Fourier-transform infrared (FTIR), proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR), and chromatographic-mass spectral (MS) analyses.