A theoretical investigation of iron-catalyzed selective hydrogenation of nitriles to secondary imines

• DOI: 10.1016/j.cplett.2020.138130
• Publication Date: 2020-10-24T23:06:25Z
• Authors: Rui-Ping Huo; Xiang Zhang; Cai-Feng Zhang; Hong-Hong Qin; Rui-Xue Wang
• Keywords: Imine; Primary (astronomy); Transition state; Condensation reaction

Abstract The mechanism of the transition metal iron complex [(iPr-PNP)Fe(H)Br(CO)] catalyzed reaction of selective hydrogenation of nitriles to secondary imines has been investigated with the M06-2X function. The results indicate that the reaction involves two basic processes: (i) A catalyzed p-bromobenzonitrile to benzaldimine and primary amine transformation; (ii) condensation of benzaldimine with a primary amine to afford secondary imine. The calculated barrier of transition metal-catalyzed condensation reaction of benzaldimine with a primary amine, 30.6 kcal/mol, indicates that the condensation reaction is feasible under experiment conditions. The theoretical results provide a deeper understanding of the mechanism and fully explain the experimental facts.