A N-heterocyclic carbene gold hydroxide complex: a golden synthon

Abstract

The synthesis and complete characterisation of a well-defined N-heterocyclic carbene bearing gold hydroxide complex, [Au(OH)(IPr)], is reported. Its reaction chemistry appears rich and diverse.

Aminkomplexe des Goldes, Teil 7: Pseudosymmetrie bei Aminkomplexen des Gold(I)-cyanids [1] / Amine Complexes of Gold, Part 7: Pseudosymmetry in Amine Complexes of Gold(I) Cyanide

“…B. Triethylphosphan [3], Triphenylphosphan [4,5], Methylisocyanid [6] oder Imidazol-2-ylidenen [7] gefunden werden. Alle diese Komplexe weisen wegen der d 10 -Konfiguration von Gold(I) dië ubliche lineare Form L-Au-CN auf.…”

Silver-free Gold(I) Catalysts for Organic Transformations

“…In subsequent studies the reactions of the hydroxide (NHC)AuOH with various Brønsted acids were investigated [17,51]. Different products were obtained with HBF 4 In most cases [(NHC)AuOH] (K) was activated in situ by addition of HBF 4 · OEt 2 in molar ratios between 2 : 1 and 1 : 2 in solvents or mixed solvents as indicated.…”

“…The most successful candidates are compounds with the bis(trifluoromethylsulfonyl)-imidate group, -N(OSO 2 CF 3 ) 2 or -NTf 2 ("triflimide"), introduced by Gagosz et al and used for complexes with L = PR 3 (I) and L = NHC (J) [28], and very recently the simple fluoride F [12] (A) and hydroxide OH [17] for L = carbene (K). Together with a number of more specialized alternatives (see also below), these catalysts are the basis of new synthetic protocols which now have allowed carrying out the preparations in a silver-free medium.…”

“…Complexes of the type [(L)AuOE] were also discovered rather late. With L = R 3 P as the auxiliary ligand, e. g. an acetate [(Ph 3 P)AuOAc] (B) was isolated in 1969 [15], and a trimethylsiloxide [(Ph 3 P)AuOSiMe 3 ] (C) in 1970 [16], followed by the first alkoxides and hydroxides with L = NHC [17] in very recent work by the group of Nolan (D, for this work and related studies on oxo and hydroxo complexes see below). In the course of the early work, the bis(trimethylsilyl)amide [(Ph 3 P)AuN(SiMe 3 ) 2 ] (E) with a then rare covalent Au-N bond was also prepared [16].…”

Synthesis of N-heterocycles through cyclization-triggered tandem additions to alkynes and the study of promoters in ionic reactions.

“…First of all, gold precatalysts like L-Au-CH3 and L-Au-OH have only been synthesized successfully for a limited set of ligands. 102,[107][108][109][110] This limitation is a constraint in gold catalysis because different gold-catalyzed reactions usually require different ligands for optimal efficiency. 67 Second, for each of the activation methods reported, only a limited set of gold-catalyzed reactions has been tested.…”