Catalytic Reductive Functionalization of CO$_2$: An Entry to Chemicals from CO$_2$

International audienceWhile greenhouse gases emissions are reaching alarming levels, fossil fuels still represent 80% of the world energy portfolio and 95% of our chemical commodities rely on non-renewable resources, namely hydrocarbons. In this context, utilizing CO$_2$ as a C$_l$ building block to produce platform chemicals as an alternative to petrochemistry has a double advantage of reusing CO$_2$ while spa ring fossil resources and avoiding C0$_2$ emissions from their use. We have developed a strategy relying on the simultaneous use of a functionalizing reagent and a reductant that can be $independently$ adjusted to perform the reductive functionalization of C0$_2$. The so-called $diagonal\ approach$ will be discussed and exemplified with novel catalytic processes to convert C0$_2$ to formamides, N-heterocycles, methylamines and methanol, using hydroboranes, hydrosilanes or formic acid as reductants. These new catalytic reactions rely on the use of simple organocatalysts or Zn, Fe and Ru organometallic complexes. The mechanisms at play in these transformations will be presented, based on DFT calculations and isolation of reactive catalytic intermediates