Highly Efficient Rh(I) Homo- and Heterogeneous Catalysts for C–N Couplings via Hydrogen Borrowing

• Published in: Inorganic chemistry Vol. 56; no. 23; pp. 14682 - 14687
• Main Authors: Wong, Chin M, Peterson, Matthew B, Pernik, Indrek, McBurney, Roy T, Messerle, Barbara A
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 04.12.2017
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.7b02586

Rhodium­(I) complexes were explored as catalysts for the hydrogen borrowing reactions of amines and alcohols. Bidentate carbene-triazole ligands were readily synthesized via “click” reactions which allowed a diversity of ligand backbones to be accessed. The catalytic transformations are highly efficient, able to reach completion in under 6 h, and promote C–N bond formation across a range of primary alcohol and amine substrates. Moreover, site-selective catalysis can be achieved using substrates with more than one reactive site. A rhodium­(I) complex covalently attached to a carbon black surface was also deployed in the hydrogen borrowing coupling reaction of aniline with benzyl alcohol. This represents the first report of a heterogeneous rhodium catalyst used for hydrogen borrowing.