Cycloaurated gold(III) complexes with monoanionic thiourea ligands

•Synthesis of range of new gold(III) thiourea complexes by simple methodology.•ESI MS identifies wide range of other species, demonstrating method generality.•Two structural determinations reveal effects of bulky cyclohexyl substitution.

Using a simple one-pot procedure, reaction of cycloaurated gold(III) dihalide complexes [LAuCl2] (L = 2-benzylpyridyl, 2-anilinopyridyl) with trisubstituted thioureas PhNHC(S)NR2 (R = Me, Cy) and Me3N in methanol, followed by addition of excess NaBPh4 gave the salts [LAu{SC(=NR2)NPh}]+BPh4- containing N,S-chelated thiourea monoanion ligands. The compounds were obtained in good yields, and were characterised by ESI MS, elemental microanalysis and in two cases by X-ray structure determinations. The series of complexes was extended by additional microscale reactions of LAuCl2 complexes (L = 2-benzylpyridyl, 2-anilinopyridyl, 2-benzoylpyridyl or picolinamide) with a wide range of trisubstituted thioureas, with products identified by ESI MS.

Graphical abstractReaction of cycloaurated gold(III) complexes [LAuCl2] (L = 2-benzylpyridyl, 2-anilinopyridyl) with a range of tri-substituted thioureas PhNHC(S)NR2 and base gives cationic complexes [LAu{SC(=NR2)NPh}]+ containing four-membered Au–S–C–N rings, isolated as their BPh4- salts.Figure optionsDownload full-size imageDownload as PowerPoint slide