Gold(I) Catalysts with Bifunctional P, N Ligands

Abstract

A series of phosphanes with imidazolyl substituents were prepared as hemilabile PN ligands. The corresponding gold(I) complexes were tested as bifunctional catalysts in the Markovnikov hydration of 1-octyne, as well as in the synthesis of propargylamines by the three component coupling reaction of piperidine, benzaldehyde, and phenylacetylene. While the activity in the hydration of 1-octyne was low, the complexes are potent catalysts for the three component coupling reaction. In homogeneous solution the conversions to the respective propargylamine were considerably higher than under aqueous biphasic conditions. The connectivity of the imidazolyl substituents to the phosphorus atom, their substitution pattern, as well as the number of heteroaromatic substituents have pronounced effects on the catalytic activity of the corresponding gold(I) complexes. Furthermore, formation of polymetallic species with Au(2), Au(3), and Au(4) units has been observed and the solid-state structures of the compounds (5)(2)Au(3)Cl(2)]Cl and (3c)(2)Au(4)Cl(2)]Cl(2) (3c = tris(2-isopropylimidazol-4(5)-yl phosphane, 5 = 2-tert-butylimidazol-4(5)-yldiphenyl phosphane) were determined. The gold(I) complexes of imidazol-2-yl phosphane ligands proved to be a novel source for bis(NHC)gold(I) complexes (NHC = N-heterocyclic carbene). 1 Gold(I) catalysts with bifunctional P,N ligands Corinna Wetzel, [a] Peter C. Kunz,* [a] Indre Thiel, [a] Bernhard Spingler [b] [a] Institut für Anorganische Chemie und Strukturchemie I, Heinrich-Heine Universität Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany. Fax: (+)49 211 8112287; E-mail:peter.kunz@uni-duesseldorf.de.

Cytotoxicity of ruthenium(II) piano-stool complexes with imidazole-based PN ligands

“…[32,[34][35][36][37] All reactions were carried out in Schlenk tubes under an atmosphere of dry nitrogen using anhydrous solvents purified according to standard procedures. All chemicals were purchased from commercial sources and used as received.…”

“…We are currently examining the use of imidazole-based PN ligands in biomedical applications [30][31][32] as well as in catalysis [33,34] . Here we present coordination chemistry of these PN ligands towards (η 6 -cymene)Ru(II) and basic cytotoxicity studies in different cancer cell lines.…”

The synthesis and transformation of 4-phosphorylated derivatives of 1,3-azoles

“…Для отримання біс-та трис[імідазол-4(5)-іл] фосфінів в серії робіт [5][6][7][8][9][10][11][12][13][14][15][16] використано 2-заміщені імідазоли, які перед фосфорилюванням також попередньо захищають по N 1 атому. Захисними використовуються стійкі до дії основ групи: СH 2 OMe та СH(OEt) 2 , які легко знімаються 20 % соляною кислотою або водним ацетоном відповідно (схема 2).…”

“…При використанні дифенілхлорофосфіну необхідно застосування більш сильної основи -третбутиллітію [12]. При цьому після зняття захисної СH 2 OMe групи в лужних умовах отримано ряд похідних імідазол-4(5)-ілдифенілфосфінів (схема 3).…”

Silver and gold-catalyzed multicomponent reactions

“…A series of new imidazole-based phosphane ligands were prepared by the research group of Kunz [35]. The corresponding Au(I) NP complexes displayed a potent catalytic activity in a model A 3 -coupling reaction.…”