Facile Synthesis of Gold(III) Aryl–Carbene Metallacycles

Abstract

New gold(III) metallacyclic complexes with unprecedented aryl−carbene bidentate ligands have been prepared by the reaction of the cycloaurated gold(III) complex [AuCl 2 (pap-C 1 ,N)] (pap = 2-(2-pyridylamino)phenyl) with isocyanide CNR (R = 2-naphthyl (1), cyclohexyl (2), or 2,6-dimethylphenyl (3)). Complexes have been spectroscopically and structurally characterized, showing in some complexes aurophilic gold(III)•••gold(III) and π−π interactions. In contrast with the starting material these complexes are emissive in the solid state, probably because of the better σ-donor properties of the new bidentate ligands.

Synthesis, characterization and catalytic activity of gold complexes with pyridine-based selone ligands

“…Both selenium atoms and two chlorine atoms of Bptp ligand adopt a cis disposition. Au-Cl av average bond distance (2.338 Å) is within the range normally found for Au-Cl bonds in Au(III) complexes [64,65]. Bond distances around the gold ion with selenium …”

(C^Npz^C)AuIIIcomplexes of acyclic carbene ligands: synthesis and anticancer properties

“…19 The authors utilised existing synthetic methodology, reacting primary amines or diamines with gold(III) isocyanide complexes to produce acyclic carbene complexes. Since then few investigations on these systems have been reported, except for a small number of papers describing cyclometallated gold(III) carbenes produced either by insertion of an isocyanide into an Au-N bond 20,21 or by nucleophilic attack of a gold-CNR complex by an amine. 22 We became interested in acyclic carbene complexes since their formation promised to present a simple way of functionalizing gold complexes with bio-inspired moieties bearing a amine functions such as amino acid derivatives.…”

Metal-Mediated Addition of N-Nucleophiles to Isocyanides: Mechanistic Aspects

“…As a result of the interaction between K 2 [PtCl 4 ] and C≡NMe and the following addition of hydrazine, the first complex of a heteroatom-stabilized carbene was obtained [ 46 , 47 , 48 , 49 ]. Since that time, the metal-mediated addition of the monofunctional O- [ 50 , 51 , 52 , 53 , 54 ], N- [ 34 , 35 , 36 , 37 , 41 , 43 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ], and other [ 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 ] nucleophiles as well as bifunctional nucleophiles [ 27 , 34 , 53 , 62 , 64 , 79 , 80 , 81 , 82 , …”

“…The N–H nucleophiles with the sp 3 type of the nitrogen orbital hybridization (e.g., amines and hydrazines) are among the most common reagents used in this reaction, and their addition to C≡NR has been intensively exploring over several decades [ 34 , 35 , 36 , 37 , 41 , 43 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 92 ], including the experimental kinetic studies [ 93 , 94 ]. However, surprisingly, despite the long history of these researches, some important aspects of the reaction mechanism still remain unknown, even for the simplest systems.…”