Rh(I) complexes bearing N, N and N,P ligands anchored on glassy carbon electrodes: Toward recyclable hydroamination catalysts

Andrey A. Tregubov, Khuong Q. Vuong, Erwann Luais, J. Justin Gooding, Barbara A. Messerle*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)

Abstract

A series of N,N-donor ligands (bis(pyrazol-1-yl)methane (bpm), bis(N-methylimidazol-2-yl)methane (bim), 1-(phenylmethyl)-4-(1H-pyrazol-1-yl methyl)-1H-1,2,3-triazole (PyT)), and one N,P-donor ligand precursor (1-(3,5-dimethylpyrazol-1-yl)(2-bromoethane) (dmPyBr)) were synthesized and functionalized with aniline. Diazotization of the aniline into an aryl diazonium, using nitrous acid in aqueous conditions, was performed in situ such that the ligands could be reductively adsorbed onto glassy carbon electrode surfaces. The N,N-donor ligands (bpm, bim, PyT) were immobilized in a single step, while several steps were required to immobilize the N,P-donor ligand (dmPyP) to prevent oxidation of the phosphine group. The complexation of the anchored ligands with the metal complex precursor ([Rh(CO)2(μ-Cl)] 2) led to the formation of anchored Rh(I) complexes with each of the ligands (bpm, bim, PyT, dmPyP). X-ray photoelectron spectroscopy (XPS) confirmed the formation of the anchored ligands as well as the anchored complexes. The surface coverage of functionalized electrodes was estimated by means of cyclic voltammetry, and the nature of the coverage was close to being a monolayer for each immobilized complex. The anchored Rh(I) complexes were active as catalysts for the intramolecular hydroamination of 4-pentyn-1-amine to form 2-methyl-1-pyrroline.

Original languageEnglish
Pages (from-to)16429-16437
Number of pages9
JournalJournal of the American Chemical Society
Volume135
Issue number44
DOIs
Publication statusPublished - 6 Nov 2013
Externally publishedYes

Fingerprint

Dive into the research topics of 'Rh(I) complexes bearing N, N and N,P ligands anchored on glassy carbon electrodes: Toward recyclable hydroamination catalysts'. Together they form a unique fingerprint.

Cite this