Reductive functionalization of CO2 with amines: an entry to formamide, formamidine and methylamine derivatives

Abstract

CO₂ utilization for the production of C₁-containing molecules is a desirable route to value-added chemicals. In this perspective, we summarize the recent results devoted to the formation of nitrogen compounds obtained by reductive functionalization of CO₂ in the presence of amines. Using mild reductants, such as molecular hydrogen, hydrosilanes and hydroboranes, novel catalytic reactions have been designed in the last few years to facilitate the reductive functionalization of CO₂ to formamide, formamidine and methylamine derivatives. While early efforts were devoted to the formylation of N–H bonds, efficient organic and metal catalysts have been developed lately to promote the complete deoxygenation of CO₂ to benzimidazoles, quinazolinones, formamidines and methylamines. Finally, the opportunities and challenges facing the practical use of CO₂ in the production of nitrogen-containing molecules are discussed.