Synthesis of a variety of key medicinal heterocyclic compounds via chemical fixation of CO2 onto o-alkynylaniline derivatives

Heterocyclic systems are not only prevalent in an extensive number of natural products and artificial compounds but also used as building blocks in organic synthesis. Over 90% of new drugs contain at least one heterocyclic fragment in their structures. Therefore, the development of new one-pot methods for the synthesis of this important family of organic compounds that benefit from inexpensive, simple, and readily available starting materials continues to be a target of intense interest. Among recent reported synthetic methods, the chemical fixation of carbon dioxide onto organic compounds are one of the most interesting and promising synthetic procedures from the viewpoint of green and sustainable chemistry. Along this line, chemical fixation of CO2 onto o-alkynylanilines has emerged over the past five years as a powerful and novel strategy to the synthesis of a variety of biologically important heterocyclic systems. In this mini review, we highlight the advances in this chemistry, with special emphasis on mechanistic aspects of the reactions.