Cyclometalated gold(iii) complexes: noticeable differences between (N, C) and (P, C) ligands in migratory insertion. Issue 16 (4th April 2018)

• Record Type: Journal Article
• Authors: Serra, Jordi; Font, Pau; Sosa Carrizo, E. Daiann; Mallet-Ladeira, Sonia; Massou, Stéphane; Parella, Teodor; Miqueu, Karinne; Amgoune, Abderrahmane; Ribas, Xavi; Bourissou, Didier
• Is Part Of: Chemical science. Volume 9:Issue 16(2018)
• Page Start: 3932
• Page End: 3940
• Publication Date: 2018-04-04
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7sc04899h
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : Gold(iii ) complexes are garnering increasing interest for opto-electronic, therapeutic and catalytic applications. Abstract : Gold(iii ) complexes are garnering increasing interest for opto-electronic, therapeutic and catalytic applications. But so far, very little is known about the factors controlling their reactivity and the very influence of the ancillary ligand. This article reports the first comprehensive study on this topic. The reactivity of a cationic (N, C) gold(iii ) complex, namely1A, towards ethylene has been thoroughly studied and compared with that of the related (P, C) complex1C . A cationic gold(iii ) complex5A resulting from double insertion of ethylene was selectively obtained. Complex5A was found to be remarkably stable. It was trapped with chloride and fully characterized. In marked contrast to that observed with1C, no β-H elimination or linear-to-branched rearrangement of the alkyl chain occurred with1A . The energy profile for the reactions of1A with ethylene has been comprehensively investigated computationally, and the influence of the ancillary ligand has been precisely delineated. Because nitrogen is a weaker donor than carbon (and phosphorus), the (N, C) ligand is very electronically dissymmetric, much more than the (P, C) ligand. This makes the two reactive sites at gold quite different, which noticeably influences the competition between migratory insertion and β-H elimination, and actually changes the outcome of the olefin insertion at gold. This study provides valuable insight into the influence of ancillary ligands on gold(iii ) reactivity, something critical to further develop Au(iii ) and Au(i )/Au(iii ) catalysis.