In‐situ Generation of An N‐Heterocyclic Carbene‐Functionalized Metal‐Organic Framework via Postsynthetic Ligand Exchange for Efficient and Selective Hydrosilylation of CO2

We report a metal‐organic framework (MOF) catalyst that realizes the CO2 to methanol transformation under ambient conditions. The MOF is one rare example containing metal‐free N‐heterocyclic carbene (NHC) moieties, which are installed using an in‐situ generation strategy involving the incorporation of an imidazolium bromide‐based linker into the MOF by postsynthetic ligand exchange. Importantly, the resultant NHC‐functionalized MOF is the first catalyst capable of perform quantitative hydrogen‐transfer from silanes to CO2, thus achieving quantitative (>99%) methanol yield. Density functional theory calculations indicate the high catalytic activity of the NHC sites in MOFs are attributed to the decreased reaction barrier of a reaction route involving the formation of an NHC‐silane adduct. In addition, the MOF‐immobilized NHC catalyst shows enhanced stability for up to eight cycles without base activation as well as high selectivity towards the desired silyl methoxide product.

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