Innovations in isocyanate synthesis for a sustainable future

Abstract

Isocyanates play a crucial role as key building blocks in the production of thermoplastic foams, elastomers, adhesives, agrochemicals, and pharmaceuticals. These compounds are essential in the manufacture of various polymeric products, such as polyurethane foams, synthetic rubbers, and surface coatings. Given their significance, and the fact that many isocyanates are highly reactive and toxic, there is an increasing demand for innovative and sustainable methods for their synthesis and detection that emphasize safety, efficiency, and selectivity. Developing processes for isocyanate production that avoid hazardous reagents like phosgene is particularly critical. While several methods exist for the in situ generation of isocyanates, the search for an eco-friendly and sustainable approach for their direct synthesis and isolation continues. Recent advances in isocyanate synthesis promise innovative and efficient strategies with broad industrial and environmental benefits. This review highlights various methods for synthesizing di- and monoisocyanates, emphasizing their isolation and conversion into ureas and carbamates in line with the principles of sustainable and green chemistry.