Complexes of gold(III) with mononegative bidentate N,O-ligands

Dar, Ajmar; Moss, Karen; Cottrill, Stephanie M.; Parish, R. V.; McAuliffe, Charles A.; Pritchard, Robin G.; Beagley, B.; Sandbank, Jennifer

doi:10.1039/dt9920001907

Cited by 53 publications

(38 citation statements)

References 6 publications

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“…When a bulky substituent is present at the β position of the starting α,β-enone, its addition to the N-1-position of the 7-azaindole system is slowed down and the complex [76] 8 may form under the reaction conditions (Scheme 7). The acid-catalyzed reaction of 8 with more hindered β-substituted α,β-enones affords the 3-substituted azaindoles 3 and regenerates the Au III catalyst.…”

Section: Resultsmentioning

confidence: 99%

Gold‐Catalyzed C‐3‐Alkylation of 7‐Azaindoles Through Michael‐Type Addition to α,β‐Enones

et al. 2006

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The AuIII‐catalyzed reactions of 7‐azaindole derivatives with α,β‐enones are described. Factors that can direct the C‐3‐ versus N‐1‐alkylation reaction on the 7‐azaindole nucleus are explored. The AuIII‐catalyzed reaction of 7‐azaindole with β‐unsubstituted α,β‐enones afforded 1‐substituted7‐azaindoles through an aza‐Michael‐type reaction. Incontrast, 6‐substituted 7‐azaindoles underwent regioselective C‐3‐alkylation through a Na[AuCl4]·2H2O‐catalyzed conjugate addition‐type reaction. Analogously, the Na[AuCl4]·2H2O‐catalyzed reaction of 7‐azaindole derivatives with β‐aryl‐substituted α,β‐enones gave 3‐substituted 7‐azaindoles in moderate‐to‐satisfactory yields. Moreover, the Na[AuCl4]·2H2O‐catalyzed reaction of 1‐substituted 7‐azaindoles with α,β‐enones allowed an easy entry to 1,3‐disubstituted 7‐azaindoles in moderate‐to‐high yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

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Section: Resultsmentioning

confidence: 99%

Gold‐Catalyzed C‐3‐Alkylation of 7‐Azaindoles Through Michael‐Type Addition to α,β‐Enones

et al. 2006

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“…In addition, the chelate complex formed is often neutral, enabling 'capture' of unstable oxidation states in metals, e.g. with tris(pyridine-2-carboxylato-N,O)manganese(III) monohydrate (Figgis, Raston, Sharma & White, 1978), and dibromo (pyridine-2-carboxylato-N,O)gold(III) (Dar et al, 1992). Also, a number of simple structures involving common transition metals and often mixed-ligand systems appear both in earlier and current literature, e.g.…”

Section: Commentmentioning

confidence: 99%

2-Carboxypyridinium Chloride Monohydrate

Smith¹,

Byriel²,

Kennard³

1995

Acta Crystallogr C

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The structure of the monohydrated polymorph of picolinic acid hydrochloride, C6H6NO~.C1-.H20, has been determined and the role of the lattice water in the hydrogen bonding to the chloride ion considered. In the anhydrous complex of the same compound, an interaction between the chloride and the pyridinium proton is found [C1... CommentPicolinic acid (pyridine-2-carboxylic acid) is of considerable interest, particularly to coordination chemists, as it possesses a potentially uninegative bidentate (N,O) donor system with the ability to stabilize complexes through the formation of six-membered chelate tings about metal centres. In addition, the chelate complex formed is often neutral, enabling 'capture' of unstable oxidation states in metals, e.g. with tris(pyridine-2-carboxylato-N,O)manganese(III) monohydrate (Figgis, Raston, Sharma & White, 1978), and dibromo (pyridine-2-carboxylato-N,O)gold(III) (Dar et al., 1992). Also, a number of simple structures involving common transition metals and often mixed-ligand systems appear both in earlier and current literature, e.g. bis (pyridine-2-carboxylato-N,O )copper(II) monohydrate (Faure, Loiseleur & Thomas-David, 1973) andThe structures of both picolinic acid (Takusagawa & Shimada, 1973) and its anhydrous hydrochloride (Laurent, 1965) have been determined. In an attempted preparation of an antimony(III) complex with picolinic acid, analogous to the trimethyl-and triphenylantimony(HI) complexes with picolinic acid (Domagala, Huber & Preut, 1990), a white crystalline solid was isolated, which was subsequently identified as a hydrated polymorph of picolinic acid hydrochloride, (I). Since this compound had not previously been reported in the literature, its structure was determined and is reported here. H•+ COOH (I).CI-.H20The planar 2-carboxypyridinium cation is conformationally similar to the anhydride (Laurent, 1965) ExperimentalThe title compound was isolated as a byproduct from the reaction mixture obtained after refluxing a 1:3 molar ratio of antimony(III) chloride and pyridine-2-carboxylic acid (picolinic acid) in water. Colourless prisms formed upon partial evaporation of the solution at room temperature. The structure was solved by direct methods using SHELXS86 (Sheldrick, 1985) and refined by full-matrix least squares (SHELXL93; Sheldrick, 1993) with anisotropic displacement parameters for all non-H atoms. H atoms were located by difference methods and included with both positional and displacement parameters refined. Other programs used wereXtal3.2 (Hall, Flack & Stewart, 1992) and PLATON (Spek, 1990).The authors acknowledge financial assistance from the Australian Research Council, the University of Queensland and the Centre for Instrumental and Developmental Chemistry of the Queensland University of Technology.Lists of structure factors, anisotropic displacement parameters and H-atom coordinates have been deposited with the IUCr (Reference: AS1154). Copies may be obtained through The Managing Editor, International Union of Crystallography, 5 Abbey Sq...

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“…It is noted that pydc has recently been used in the preparation of polymeric Ln(III)/Cu, Ag, Zn mixed metal complexes [7][8][9][10]. However, only few transition metal complexes containing pydc have been synthesized [11][12][13][14][15][16][17] 1 In all the preparations, mixed metal Mn/alkali, Mn/Zn and Mn/Nd materials were adopted to attempt to produce mixed metal pydc complexes. However, only 2 contains mixed MnK 2 metals, while 3 and 4 contain sole Zn and Nd, respectively, indicating that Zn and Nd have better affinity for oxygen than Mn has.…”

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confidence: 99%

“…It is noted that pydc has recently been used in the preparation of polymeric Ln(III)/Cu, Ag, Zn mixed metal complexes [7][8][9][10]. However, only few transition metal complexes containing pydc have been synthesized [11][12][13][14][15][16][17]. In order to develop the metal-pydc coordination chemistry including transition metal, lanthanide and mixed metals, four complexes [Mn(phen)(pydc)] n (1), [K 2 Mn(pydc) 2 (H 2 O) 5 ] n (2), [{Zn(pydc)(H 2 O) 2 } AE (H 2 O)] n (3) and [{Nd 2 (pydc) 2 (Hpydc) 2 (H 2 O) 4 } AE 2H 2 O] n (4) were prepared by both conventional solution syn-1387-7003/$ -see front matter Ó…”

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confidence: 99%