Unleashing the Potential of a Zr-MOF for Selective Amine and Imine Synthesis: An Efficient Heterogeneous Catalyst

While amines and imines are extremely relevant chemicals, their selective synthesis has remained elusive. Subject to exploration, metal-organic frameworks (MOFs) could offer a promising platform for catalysis. We prepared a MOF-based catalytic system, UiO-66-NH₂-PC-M (M = Co, Ni, and Zn), which entrenched routes for efficient and selective synthesis of amines and imines via borrowing hydrogen (BH) and aerobic coupling (AC) reactions. By carefully selecting MOF catalysts and a base, we successfully transformed a range of starting materials achieving high selectivity, including alcohols, amines, and carbonyl compounds, into value-added amines or imines. Coupled with a solvent exchangeable feature, the MOF catalysts, acting as hosts, facilitate the BH and AC processes, providing a controlled environment for the reactions. Density functional theory (DFT) calculations synchronized well with experiments, illustrating catalytic mechanism and efficacy. Further, the catalytic platform developed is distinct for its recyclable nature, broad substrate scope, and operational simplicity, making it a valuable addition to the toolkit of synthetic chemists. As sustainable and eco-friendly synthetic processes are in rising demand, this work underscores the potential of MOFs as a versatile catalyst in developing more efficient and greener synthetic strategies for amines and imines. This work is the first demonstration of the catalytic efficacy of MOFs in the selective synthesis of amine and imine with high yields.