Base Metal Catalyst for Indirect Hydrogenation of CO2

We herein reporta novel Mn-SNS-based catalyst, which is capableof performing indirect hydrogenation of CO2 to methanol via formylation. In this domain of CO2 hydrogenation,pincer ligands have shown a clear predominance. Our catalyst is basedon the SNS-type tridentate ligand, which is quite stable and cheapas compared to the pincer type ligands. The catalyst can also be recycledeffectively after the formylation reaction without any significantchange in efficiency. Various amines including both primary and secondaryamines worked well under the protocol to provide the desired formylatedproduct in good yields. The formed formylated amines can also be reducedfurther at higher pressures of hydrogen. As a whole, we have developeda protocol that involves indirect CO2 hydrogenation tomethanol that proceeds via formylation of amines.