Gold-Catalyzed Suzuki Coupling of ortho-Substituted Hindered Aryl Substrates

Chem Asian J. 2017 Feb 16;12(4):459-464. doi: 10.1002/asia.201601583. Epub 2017 Jan 18.

Abstract

A method that allows hindered ortho-substituted aryl iodides to be efficiently coupled to phenylboronic acid using a gold-catalyzed C-C bond formation is presented. The use of a molecularly-defined dinuclear gold chloride catalytic precursor that is stabilized by a new tetradentate (N,N')-diamino-(P,P')-diphosphino ferrocene hybrid ligand in a Suzuki-type reaction is described for the first time. Electron-rich isopropyl groups on phosphorus were found essential for a superior activity, while the performances of a set of analogous gold dinuclear complexes that were fully characterized by multinuclear NMR spectroscopy and XRD analysis, were investigated. Therefore, arylation of para and ortho-substituted iodoarenes bearing electron-rich, electron-poor functional groups, and even hindered polycyclic aromatic compounds is described.

Keywords: Suzuki coupling; functionalized ferrocenes; gold; halides; hybrid (P, N)-ligands.