Effect of the ancillary ligand in N-heterocyclic carbene iridium(III) catalyzed N-alkylation of amines with alcohols. (1st September 2021)

• Record Type: Journal Article
• Authors: Feng, Xinshu; Huang, Ming
• Is Part Of: Polyhedron. Volume 205(2021)
• Publication Date: 2021-09-01
• Subjects: N-heterocyclic carbene -- Iridium -- N-alkylation of amines with alcohols -- Methanol; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2021.115289
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: NHC-Ir(III) complexes bearing various combinations of chlorine, pyridine and NHC ligands were assayed as active catalysts for the N -alkylation of amines with alcohols under mild conditions. Abstract: A series of air-stable N -heterocyclic carbene (NHC) Ir(III) complexes (Ir1 -6 ), bearing various combinations of chlorine, pyridine and NHC ligands, were assayed for the N -alkylation of amines with alcohols. It was found that Ir3, with two monodentate 1, 3-bis-methyl-imidazolylidene (IMe) ligands, emerged as the most active complex. A large variety of amines and primary alcohols were efficiently converted into mono- N -alkylated amines in 53–96% yields. As a special highlight, for the challenging MeOH, selective N -monomethylation could be achieved using KOH as a base under an air atmosphere. Moreover, this catalytic system was successfully applied to the gram-scale synthesis of some valuable compounds.