Selective Construction of a Biomass-Based Secondary Amine by Hydrogenative Homocoupling of Nitrile Using an Iridium Complex in a Metal–Organic Framework

• Published in: ACS catalysis Vol. 13; no. 15; pp. 10261 - 10281
• Main Authors: Zhou, Jiamin, Liang, Meixiang, Chen, Jinzhu
• Format: Journal Article
• Language: English
• Published: American Chemical Society 04.08.2023
• Subjects: biomass; secondary amine; kinetics; metal−organic frameworks; hydrogenative coupling
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/acscatal.3c00831

Reductive amination of furfural was recently investigated as a straightforward method for the construction of biomass-based primary amine (furfurylamine) and tertiary amine [tris(2-furanylmethyl)­amine] with, however, secondary amine [bis(2-furanylmethyl)­amine] as a problem due to a selectivity issue. In this research, we demonstrated a highly selective and efficient strategy for the construction of bis(2-furanylmethyl)­amine in 99% yield by Ir-catalyzed hydrogenative homocoupling of biomass-based 2-furanacarbonitrile in one pot. The Ir catalyst was prepared by immobilization of the [Cp*Ir­(bpy)­Cl]­Cl complex in a 2,2′-bipyridine-functionalized UiO-67. Both furfurylamine and furfurylamine-derived secondary imine were successively detected as intermediates. Detailed kinetic analysis suggested the secondary imine hydrogenation as the rate-determining step instead of 2-furanacarbonitrile hydrogenation. A variety of symmetry secondary amines (18 examples) were selectively prepared in excellent to moderate yields from the corresponding nitriles with the Ir catalyst. This research thus built a bridge between a well-defined single-site catalyst with a metal–organic framework as ligand/support and its homogeneous counterpart to understand kinetic details in the biomass-based amine formation.