Synthesis and Antimicrobial Activity of the Pathogenic E. coli Strains of p-Quinols: Additive Effects of Copper-Catalyzed Addition of Aryl Boronic Acid to Benzoquinones

A mild and efficient protocol for the synthesis of p-quinols under aqueous conditions was developed. The pivotal role of additives in the copper-catalyzed addition of aryl boronic and heteroaryl boronic acids to benzoquinones was observed. It was found that polyvinylpyrrolidone (PVP) was the most efficient additive used for the studied reaction. The noteworthy advantages of this procedure include its broad substrate scope, high yields up to 91%, atom economy, and usage of readily available starting materials. Another benefit of this method is the reusability of the catalytic system up to four times. Further, the obtained p-quinols were characterized on the basis of their antimicrobial activities against E. coli. Antimicrobial activity was further compared with the corresponding 4-benzoquinones and 4-hydroquinones. Among tested compounds, seven derivatives showed an antimicrobial activity profile similar to that observed for commonly used antibiotics such as ciprofloxacin, bleomycin, and cloxacillin. In addition, the obtained p-quinols constitute a suitable platform for further modifications, allowing for a convenient change in their biological activity profile.

Automated summary

A mild and efficient method for synthesizing p-quinols under aqueous conditions was developed. The key role of additives in the copper-catalyzed addition reaction of aryl and heteroaryl boronic acids to benzoquinones was observed, with polyvinylpyrrolidone (PVP) being the most efficient additive. This method offers advantages such as broad substrate scope, high yields, atom economy, and use of readily available starting materials, as well as the reusability of the catalytic system. The obtained p-quinols showed antimicrobial activity similar to commonly used antibiotics and can be further modified for different biological activities.