2,2'-Bibenzimidazole-Based Hyper-Cross-Linked Polymer Supported-Iridium Complex: A Recyclable Metal-Polymer Ligand Bifunctional Catalyst for the α-Methylation of Arylacetonitriles with Methanol.

A metal-polymer ligand bifunctional catalyst Cp*Ir@HCPs-(2,2'-BiBzlmH2) was synthesized by the coordinative immobilization of [Cp*IrCl][Cl] on HCPs-(2,2'-BiBzlmH2). In the presence of a catalyst (1 mol % Ir) and Cs2CO3 (0.2 equiv), the α-methylation of arylacetonitriles with methanol was performed at 125 °C for 12 h to give desirable products in high yields. More importantly, the catalyst could be recycled without an obvious loss of activity during six cycles. Mechanistic experiments revealed that NH functional groups in the ligand are crucially important for hydrogen transfer.