Hans-Albert Brune

Untersuchungen zum Mechanismus der Rhodium(I)-katalysierten Hydrogen-Transfer-Reaktion von sekundären Alkoholen auf Imine

Abstract The results of a series of systematically performed experiments form the basis for a model that elucidates the catalytic cycle of the hydrogen transfer reaction from 2-propanol to imines forming secondary amines in the presence of Wilkinsons catalyst.

UV-SPEKTROSKOPISCHE UND PHOTOCHEMISCHE UNTERSUCHUNGEN AM DIBENZOPLATINOL-SYSTEM

Abstract The dibenzoplatinol system has been irradiated with monochromatic UV-radation of wavelengths λ = 253.2, 278.8, 313.7, 348.1 nm and studied with respect to photochemical reactivity. All 15 compounds were completely photo-stable within the cited wavelength interval. The results are discussed with respect to the mechanism of the reductive elimination of the biphenyl system from cis-bis(phenyl)platinum(II) complexes.

Synthesen substituierter Trimethyl(naphthyl)stannane und Tri(n-butyl)(naphthyl)stannane

Abstract Compounds of the type trimethyl(naphth-l-yl) stannane and tri(n-butyl)(naphth-l-yl)stannane with differing substituents in the 2- or 4-position of the naphthyl ligands have been synthesized as precursors to the formation of substituted naphthylplatinum compounds.

Synthesen von Aryl-Platin-Verbindungen mit großflächigen Aryl-Liganden

The syntheses of the organoplatinum compounds, (1,2,5,6-η4-cycloocta-1,5-diene)platinum(II) (5b, c), bis(aryl)(2,3,5,6-η4-bicyclo[2.2.1]hepta-2,5-diene)platinum(II) (8a–d), cis-bis(atyl)bis(triphenylphosphane)platinum(II) (9a–d), and chloro(aryl)(2,3,5,6-η4-bicyclo[2.2.1]hepta-1,5-diene)platinum(II) (10a), with the large area ligands 9-anthracenyl (a), 9-phenanthrenyl (b), 5-acenaphthenyl (c), and 1-pyrenyl (d) by use of the organotin method with aryltri(n-butyl)stannanes (3a–d) are described.

Synthesen von Bis(naphthyl)platin(II)-Verbindungen

Abstract The bis(naphthyl)platinum(II) compounds with substituents in the 2- or 4-positions of the naphthyl ligands, (1,2,5,6-η4-cycloocta-1,5-diene)bis(naphth-1-yl)platinum(II), (1,2,5,6-η4-hexa-1,5-diene)bis(naphth-1-yl)platinum(II) (2,3,5,6-η4-bicyclo[2.2.1]hepta-2,5-diene)bis(naphth-1-yl)platinum(II), cis-bis(dimethylsulfoxide)bis-(naphth-1-yl)platinum(II) and cis-bis(naphth-1-yl)bis(triphenylphosphane)platinum(II), have been synthesized from the organo-tin compounds trimethyl(naphth-1-yl)-stannane or tri(n-butyl)(naphth-1-yl)stannane with substituents in analogous positions.

Synthese und struktur des Bis[tetra(n-butyl)ammonium]-bis{[μ-bromo]2,2′-η2-[4,4′-bis(trifluormethyl) biphenyl]-platinat(II))}

Abstract Attempts to synthesize anionic biphenyl complexes of platinum resulted in the isolation of the binuclear compound bis[tetra(n-butyl)ammonium]bis{μ-bromo-2,2′η 2 -[4,4′-bis(trifluoromethyl)biphenyl]platinate(II)}. The structure has been determined by X-ray analysis.

Einflüsse von in para-Position zum Phosphor eingeführten Substituenten in das Diop-System auf die optische Induktion bei der asymmetrischen Hydrierung von Acylamino-acrylsäureethylester und (Z)-Acylamino-zimtsäuremethylester mit kationischen Rhodium-(Diop-Derivat)-Komplexen. I

Abstract (R,R)-Diop was modified at the diphenylphosphino group by the introduction of substituents in para-position to the phosphorus atoms. The influence of the substituents on the optical induction was examined for the hydrogenation of ethyl α-acylaminoacrylate (AAEE) and (Z)-methyl α-acylaminocinnamate (AZME) with [Rh(diop-derivat)(solvent)2]+ BF4− as catalyst. For both substrates the substituents affected the optical induction markedly. The observed effects can be attributed to the electronical features, solvation and in special cases also to the size of the substituents.

Synthesen substituierter 9,9-bis(n-butyl) dibenzostannole

Abstract Syntheses of the five 9,9-Bis(n-butyl)dibenzostannoles are reported, which are each symmetrically disubstituted by two F 3 C-, CH 3 O-, (CH 3 ) 3 C-substituents in the 3- and 6-positions or by two F 3 C- CH 3 O-substituents in the 2- and 7-positions of the benzo rings.

Synthesen von Aryl(halogeno)platin(II)-Verbindungen mit groβflächigen und sterisch anspruchsvollen Aryl-Liganden

Abstract The usefulness of the reaction between trialkyl(aryl)stannanes and dihalogeno(η 4 -diene)platinum(II) has been tested with regard to the synthesis of sterically hindered (aryl)(halogeno)(η 4 -diene)platinum(II) compounds. As examples for the utility of the method the following complexes have been prepared: (aryl)(chloro)(1,2,5,6-η 4 -cycloocta-1,5-diene)platinum(II) (aryl = 1-naphthyl; 2-methylnaphth-1-yl; 2-ethoxynaphth-1-yl), (1,2,5,6-η 4 -cycloocta-1,5-diene)(iodo)(1-naphthyl)platinum(II) and (aryl)(chloro)(2,3,5,6-bicyclo[2.2.1]hepta-2,5-diene)-platinum(II) (aryl = 1-naphthyl; 2-methylnaphth-1-yl; 2-methoxynaphth-1-yl; 2-ethoxynaphth-1-yl; 9-anthracenyl).

Untersuchungen zum mechanismus der reduktiven photo-eliminierung des biphenyl-systems aus cis-bis(phenyl) platin(II)-verbindungen

Abstract In compounds of the type [(η 2 -diphosphine)bis(phenyi)platinum(II)] (diphosphine = 1,2-bis(diphenylphosphino)ethane, cis -1,2-bis (diphenylphosphino)ethene, 1,2-bis(diphenylphosphino)benzene), substituents of increasing van der Waals volumes have been introduced into the ortho - or meta -positions of the platinum-bonded phenyl rings in order to influence the relative orientations of these rings with espect to the plane defined by the four valences of the central platinum. The consequences of the different conformations on the photochemical elimination of the biphenyl system from the bis(phenyl)platinum compounds have been studied in the crystalline and liquid phases, with the result that such elimination can only occur if both phenyl rings are orientated perpendicular (or nearly perpendicular) to the platinum plane.