Reductive functionalization of CO2 for the synthesis of valuable compounds remains an important and challenging reaction in synthetic organic chemistry.1 Transition metal-catalyzed reductive functionalization of CO2 has become one of the most versatile, selective, and atom-economic reactions in this field as the produced formamide derivatives find high synthetic utility in organic, polymer and agro chemistry.2 Use of the noble metal such as Ruthenium and Rhodium based complexes in this transformation are well studied in the literature.3 Later researchers have focused on the usage of non-precious metal in combination with diverse specially designed supporting ligands using H2 or hydrosilane as a reducing agents.4 However, in majority of the cases, use of expensive metals, sensitive/toxic phosphine ligands, higher catalyst loadings, harsh reaction conditions (high reaction temperature or high pressure of CO2/H2) are necessary which restrict the broad applicability of these systems. Further, it has been well-established that both the metal and ligand play an important role in improving the catalytic activity of a complex and along this line, use of an NHC ligand could be beneficial due to its strong -donating nature5 resulting in a stable metal-ligand complex, which hinders any unwanted ligand dissociation during the catalytic cycle. Moreover, because of the low abundance, high price, and toxicity of heavier transition metals, there has been a continuous urge for economical but effective base metal derived catalyst systems. In this presentation, starting with the various noble/non-noble metal systems followed by the development of NHC-based zinc system for N-formylation of amines with CO2 will be discussed in details. Real Money Rummy proposal and some preliminary results as well as future plans will also be presented.

References:
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