Recent Advances in the Fixation of CO₂ into Quinazoline and Benzimidazole

Abstract

CO 2 is an important component of the atmosphere that helps in balancing the Earth's atmospheric temperature and channelizes the food cycles. However, an increase or decrease in the concentration will severely affect the climate. Particularly, the rise in CO 2 levels has immensely contributed to global warming, resulting in elevated atmospheric temperature, altered precipitation patterns, glacier melting, and subsequent rises in sea levels, impacting human well-being. In response, researchers are exploring strategies to capture and convert CO 2 into valuable products, such as methanol, formic acid, and organic compounds. Particularly, the synthesis of organic compounds using CO 2 , like benzimidazole and quinazolines, has a high impact. Benzimidazole, widely used in medicinal chemistry for treating cancer and stomach ulcers, also exhibits antiviral and antifungal properties. Quinazoline derivatives, essential in drugs like prazosin and doxazosin, have applications in treating post-traumatic stress disorder and Alzheimer's disease. These compounds were synthesized mainly using environmentally harmful synthons such as phosgene and potassium cyanide. To address both environmental and health concerns, researchers are delving into the chemical fixation of CO 2 for sustainable and green production. Catalysis emerges as a key principle in green chemistry, with catalysts reducing activation energy and facilitating sustainable processes. This review discusses recent state of the art on the development of various catalysts for conversion of CO 2 to quinazoline and benzimidazole, through various homogeneous and heterogeneous catalysts. Notably, while homogeneous catalysts lack industrial recyclability, heterogeneous catalysts show promise for large-scale implementation. This comprehensive review discusses the mechanistic aspects with DFT studies in understanding the catalysts better. Toward the end, it gives the future scope and aspects on this subject.