Sustainable carbon-based materials as heterogeneous catalysts in solvent-free acetylation reactions

The preparation of activated carbons has received a great deal of attention in recent years because of the versatility of their properties and the ‘greenness’ of the materials themselves. In the field of chemistry the development of activated carbons has led to the enhancement of numerous catalytic reactions, such as the synthesis of α,β-unsaturated nitriles, chalcones, N-alkylation of imidazoles, and epoxide ring opening reactions.

Acetylation, due to its simplicity, is one of the reactions most frequently used in the chemical and pharmaceutical industry as a method of protecting hydroxyl groups. This is the reason why numerous catalysts have been reported. Many catalysts, despite their usefulness, present some limitations, such as low regioselectivity, high cost, and/or generation of polluting by-products. There is ongoing interest in developing catalysts that are more environmentally benign while keeping a high catalytic activity.

In this work, we have designed, developed, and characterised activated carbons of acid or basic character. These materials have been tested as heterogeneous catalysts in the acetylation reaction of primary and secondary alcohols. The experiments carried out show good catalytic activity, whose magnitude depends on the type of carbon used. This protocol presents several of the characteristics related to the sustainability of chemical processes, such as, the innocuous nature and the affordable cost of the catalytic material, the absence of reaction solvent, and the ease of reaction-medium work-up. Results, experimental details, and the rationalization thereof will be presented in this meeting.