Chiral Au^I‐ and Au^III‐Isothiourea Complexes: Synthesis, Characterization and Application

Abstract

During an investigation into the potential union of Lewis basic isothiourea organocatalysis and gold catalysis, the formation of gold‐isothiourea complexes was observed. These novel gold complexes were formed in high yield and were found to be air‐ and moisture stable. A series of neutral and cationic chiral gold(I) and gold(III) complexes bearing enantiopure isothiourea ligands was therefore synthesized and fully characterized. The steric and electronic properties of the isothiourea ligands was assessed through calculation of their percent buried volume and the synthesis and analysis of novel iridium(I)‐isothiourea carbonyl complexes. The novel gold(I)‐ and gold(III)‐isothiourea complexes have been applied in preliminary catalytic and biological studies, and display promising preliminary levels of catalytic activity and potency towards cancerous cell lines and clinically relevant enzymes.

Chirality in gold(III) homodimeric complexes

“…In the crystal structure (Fig. 2a), as previously observed, 6 aurocycle 5 was almost planar because of the ionic interactions between the protonated nitrogen atom and the metallic center (distances: 2.953, 2.973 Å). Non-covalent interactions between two molecules of 5 could also be envisaged (Fig.…”

“…Such complexes will be tested on the model reactions proposed in the literature. [2][3][4][5][6][7]12…”

P,N-Chelated Gold(III) Complexes: Structure and Reactivity

“…Hence, we initially prepared the 1 -Au­(I) phosphine complex and subsequently oxidized it to [ 1 -Au­(III)]­SbF 6 (Scheme b–d). The preparation of ligated gold­(III) complexes by the oxidation of gold­(I) complexes with dichloro­(phenyl)-λ 3 -iodane − or Br 2 − was previously proven to be efficient. The 1 -Au­(I) complex was prepared in quantitative yields by mixing chloro­(dimethyl sulfide)-Au­(I) and ligand 1 in dichloromethane (Scheme b).…”

Chiral Gold(III) Complexes: Synthesis, Structure, and Potential Applications

“…In 2019, while synthesizing a series of chiral isothiourea gold(I) complexes supported by NHC‐ and phosphane‐ ligands, Smith and Nolan reported the chiral thiazolopyrimidine gold(III) trichloride 65 and 66 complexes as well as their opposite enantiomers 67 and 68 , with yields above 96 % and synthesized by oxidation of neutral isothiourea gold(I) chloride complexes with dichloroiodobenzene (PhICl 2 ), at room temperature, in dichloromethane [44] . No oxidation at the sulfur position was observed.…”