Feng Shi, Youquan Deng, Tianlong SiMa
Jul 21, 2003
Citations
2
Influential Citations
219
Citations
Quality indicators
Journal
Angewandte Chemie
Abstract
N-containing compounds such as isocyanates, carbamates, and N,N’-disubstituted urea derivatives are important chemicals. For example, the world production of isocyanates exceeded 5 megatons in 2001. Currently, these chemicals are mainly manufactured by the phosgenation of amines . The worldwide production of phosgene ranges from 6–8 megatons per year, which have been used mainly (> 85%) for the synthesis of isocyanates and their derivatives. Therefore, as a first step, the use of an alternative to phosgene in the synthesis of isocyanates should be found to help eliminate the use of phosgene altogether. Many strategies for nonphosgene routes, including reductive carbonylation and oxidative carbonylation by using CO as carbonyl source, and the use of Pd, Ru, Rh, Fe, Ni, Co, Mn, Se, Au, and W catalysts, have been extensively studied. The progress in this field of research, however, is relatively slow. Carbon monoxide is also poisonous and the mixing of CO and O2 for oxidative carbonylation is potentially explosive. As an alternative, the use of dimethyl carbonate or dimethyl sulfate as phosgene substitutes are relatively expensive for commercial applications. Therefore, the most desirable option to avoid phosgene is to replace it with CO2 directly. Besides the abundance of CO2 and its environmentally benign nature, a process that uses CO2 has the benefit of recycling carbon from the atmosphere when its use is linked with other processes that emit CO2. The detrimental influence of CO2 as a “green house” gas has