Copper carbenoid mediated N-alkylation of imidazoles and its use in a novel synthesis of bifonazole
摘要:
1H-Imidazoles are readily N-alkylated by a Cu(acac)(2) mediated reaction with alpha-diazocarbonyl compounds or with diazoalkanes generated in situ from the corresponding p-toluensulfonyl hydrazones. The antifungal agent bifonazole was prepared by the latter method. (C) 2004 Elsevier Ltd. All rights reserved.
Threitol-Strapped Manganese Porphyrins as Enantioselective Epoxidation Catalysts of Unfunctionalized Olefins
摘要:
Nine members of a family of new chiral porphyrins have been prepared from reactions between ditosylthreitol derivatives and 5,10,15,20-tetrakis(2-hydroxyphenyl)porphyrin. The assignment of the resultant isomers has been made from their H-1 NMR spectra and on the basis of an absolute configuration determination from the crystal structure of 4. The chiral frameworks of these systems are easily varied by condensing different aldehydes and ketones with the 2,3-diol of the threitol unit. The manganese derivatives of six of these systems were studied as asymmetric catalysts in the epoxidation of unfunctionalized olefins. Up to 88% ee is obtained in the epoxidation of 1,2-dihydronaphthalene with one of these derivatives, 9, when a bulky imidazole ligand is used to block the unhindered face of the porphyrin catalyst.
USE OF PT-AND PD-BIS-AND TETRA-CARBON COMPLEXES WITH BRIDGED CARBON LIGANDS IN OLEDS
申请人:Strassner Thomas
公开号:US20090326237A1
公开(公告)日:2009-12-31
The use of Pt- and Pd-bis- and tetracarbene complexes with bridged carbene ligands in organic light-emitting diodes, organic light-emitting diodes comprising at least one aforementioned Pt- or Pd-carbene complex, at least one transition metal-carbene complex of the general formula I and/or II, organic light-emitting diodes where the at least one transition metal-carbene complex of the general formula I and/or II is present in the light-emitting layer, a blocking layer for electrons, a blocking layer for excitons and/or a blocking layer for holes, a light-emitting layer comprising at least one aforementioned Pt- or Pd-carbene complex, organic light-emitting diodes comprising at least one inventive light-emitting layer, and devices which comprise at least one inventive organic light-emitting diode.
Ruthenium Catalysts for Hydrogenation of Aromatic and Aliphatic Esters: Make Use of Bidentate Carbene Ligands
作者:Felix A. Westerhaus、Bianca Wendt、Andreas Dumrath、Gerrit Wienhöfer、Kathrin Junge、Matthias Beller
DOI:10.1002/cssc.201200825
日期:2013.6
Committed carbenes: The convenient application of bidentatecarbeneligands is described for the hydrogenation of carboxylic acid esters. The ligand precursors are easily synthesized through the dimerization of N‐substituted imidazoles with diiodomethane. The catalyst is generated in situ and exhibits good activity and functional group tolerance for the hydrogenation of aromatic and aliphatic carboxylic
A variety of chiral and achiral imidazoliumsalts is synthesized. Methylene-, ethylene-, propylene- and pyridinyl-bridged bis(imidazolium) halides are used to generate the respective free chelating carbenes. The synthesis of palladium complexes of general formula [cis-CH 2 NC(H)=C(H)N(R)C} 2 PdX 2 ] with these chelating N-heterocyclic carbene ligands is reported. Structural proofs of complexes 28
Neutral Dinuclear Silver(I)–NHC Complexes: Synthesis and Photophysics
作者:Alexander Poethig、Thomas Strassner
DOI:10.1021/om200860y
日期:2011.12.26
We report the synthesis and characterization of a new anionic pincer-type μ2-η2(1κCcarbene:2κC′carbene)–C*–N–C*) ligand with a triazine core. Hydrolysis of one chloro substituent of the cyanuric chloride leads to the hydroxy-2,4-dichloro-1,3,5-triazine and the corresponding bis(imidazolium) salts, which, after deprotonation, serve as monoanionic ligands. Treatment of the bis(imidazolium) precursor with
Structure and Dynamics of Imidazolium- and Pyridinium-Substituted η<sup>3</sup>-Cycloheptatrienide-Pd Complexes
作者:Christian Jandl、Karl Öfele、Fritz E. Kühn、Wolfgang A. Herrmann、Alexander Pöthig
DOI:10.1021/om500738d
日期:2014.11.24
Their full characterization is reported along with DFT studies of their formation and special properties. The target compounds represent the first crystallographically characterized monomeric allyl complexes of a Pd dihalide. The cationic substituents on the cycloheptatrienide ring form strong intramolecular H-bonds to one bromide ligand. The Pd–allyl bond was found to be highly fluxional, showing a continuous