2,2′-Methylenebibenzimidazole-Based Hyper-Cross-Linked Polymer-Supported-Iridium Complex: A Recyclable Metal–Polymer Ligand Bifunctional Catalyst for the Auto-tandem Synthesis of <i>N</i> -Methyl Tertiary Amines from Imines and Methanol

A metal-polymer ligand bifunctional catalyst Cp*Ir@HCPs-(2,2'-CH₂BiBzlmH₂) was designed and synthesized by the coordinative immobilization of [Cp*IrCl₂] on HCPs-(2,2'-CH₂BiBzlmH₂). In the presence of a catalyst (1 mol % Ir) and Cs₂CO₃ (0.3 equiv), a series of <i>N</i>-methyl tertiary amines were obtained from imines and methanol via autotandem transfer hydrogenation/<i>N</i>-methylation. More importantly, the catalyst could be recycled without an obvious loss of activity during six cycles. Apparently, the designed catalyst combines the advantages of both homogeneous and heterogeneous catalysts.