Sulfonic Acid-Functionalized (Bio)Materials as Catalysts for Efficient Amide Bond Synthesis

Sulfonic acid carbon-(bio)based and natural clays-based catalysts were prepared and investigated for the first time as heterogeneous catalysts for amide bond synthesis by a Ritter reaction. The different SO3H-catalysts were screened using benzyl alcohol and acetonitrile as model substrates, and MWCNT-CSP revealed to be an efficient catalyst, affording the amide in 75 % yield. The practical utility of the catalysts was demonstrated by a diverse range of amides, obtained from alcohols and nitriles, in moderate to good yields. Biomass derived platform alcohols, such as 5-HMF and furfuryl alcohol, were also tested as potential building blocks for the synthesis of biopolymers. The SO3H-catalysts revealed to be a highly efficient and environmentally friendly alternative to the conventional acid catalysts commonly used in the Ritter reaction.

Automated summary

In this study, sulfonic acid carbon-based and natural clays-based catalysts were prepared and investigated for the synthesis of amide bonds by a Ritter reaction. MWCNT-CSP was found to be an efficient catalyst with a yield of 75% using benzyl alcohol and acetonitrile as model substrates. The catalysts showed practical utility in synthesizing a diverse range of amides from alcohols and nitriles, and biomass derived platform alcohols were also tested as potential building blocks. The sulfonic acid catalysts proved to be a highly efficient and environmentally friendly alternative to conventional acid catalysts in the Ritter reaction.