scispace - formally typeset
Search or ask a question
Author

Rüdiger Selke

Bio: Rüdiger Selke is an academic researcher from University of Rostock. The author has contributed to research in topics: Asymmetric hydrogenation & Catalysis. The author has an hindex of 18, co-authored 51 publications receiving 988 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: In this article, a synthesis of the title ligand is described in which the key step is the dilithiation of 1,1'- bis (dimethylaminomethyl)-3,3'-biindolyl and electrophilic trapping with ClPPh 2.
Abstract: A synthesis of the title ligand is described in which the key step is the dilithiation of 1,1'- bis (dimethylaminomethyl)-3,3'-biindolyl and electrophilic trapping with ClPPh 2 . Concomitant N-deprotection and resolution with bis [(R)-dimethyl(1-(1-naphthyl) ethylaminato-C 2 ,N)palladium chloride] led to selective recovery of the S-enantiomer. The N-dimethylaminomethyl-substituted biindolyl, but not the parent compound, showed strongly second-order behaviour for 13 C NMR peaks in the region of the phosphorus atom due to a desymmetrising 13 C-induced isotope shift of the 31 P resonance.

95 citations

Journal ArticleDOI
TL;DR: In this paper, a selectivity increase for asymmetric hydrogenation in aqueous solution from 1.5%ee (blank experiment) up to 78%EE (amphiphiles present) may be accounted for by inclusion of the catalyst into micellar aggregates.
Abstract: A selectivity increase for asymmetric hydrogenation in aqueous solution from 1.5%ee (blank experiment) up to 78%ee (amphiphiles present) may be accounted for by inclusion of the catalyst into micellar aggregates. The relative enantioselectivity Qa/b is distinctly higher for the rhodium chelate 1, carrying a hydroxy group, than for the related DIOP complex 2. The effect is minimized in the presence of increasing amounts of methanol, which is known to prevent micelle formation.

55 citations

Journal ArticleDOI
TL;DR: In this paper, the 2,3-bisphosphite derivatives of phenyl 4,6- O -benzylidene-β-D-glucopyranoside leads to new chelating ligands.
Abstract: The synthesis of the 2,3-bisphosphite derivatives of phenyl 4,6- O -benzylidene-β-D-glucopyranoside leads to new chelating ligands. Their rhodium(I) and platinum(II) complexes have been tested as catalysts for the asymmetric hydroformylation of vinyl acetate, allyl acetate and p -methoxystyrene. Good regioselectivity (>90% branched product), but an enantioselectivity of only ≤36% ee were found under mild reaction conditions (25–40°C, 40–70 bar syngas).

52 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: The discussion includes an analysis of trends in catalyst activity, a description of catalysts coordinated with N-heterocyclic carbene ligands, and an overview of ongoing work to improve the activity, stability, and selectivity of this family of L2X2Ru=CHR complexes.
Abstract: In recent years, the olefin metathesis reaction has attracted widespread attention as a versatile carbon−carbon bond-forming method. Many new applications have become possible because of major advances in catalyst design. State-of-the-art ruthenium catalysts are not only highly active but also compatible with most functional groups and easy to use. This Account traces the ideas and discoveries that were instrumental in the development of these catalysts, with particular emphasis on (PCy3)2Cl2RuCHPh and its derivatives. The discussion includes an analysis of trends in catalyst activity, a description of catalysts coordinated with N-heterocyclic carbene ligands, and an overview of ongoing work to improve the activity, stability, and selectivity of this family of L2X2RuCHR complexes.

3,229 citations

Journal ArticleDOI
TL;DR: The increasing demand to produce enantiomerically pure pharmaceuticals, agrochemicals, flavors, and other fine chemicals has advanced the field of asymmetric catalytic technologies, and asymmetric hydrogenation utilizing molecular hydrogen to reduce prochiral olefins, ketones, and imines has become one of the most efficient methods for constructing chiral compounds.
Abstract: The increasing demand to produce enantiomerically pure pharmaceuticals, agrochemicals, flavors, and other fine chemicals has advanced the field of asymmetric catalytic technologies.1,2 Among all asymmetric catalytic methods, asymmetric hydrogenation utilizing molecular hydrogen to reduce prochiral olefins, ketones, and imines, have become one of the most efficient methods for constructing chiral compounds.3 The development of homogeneous asymmetric hydrogenation was initiated by Knowles4a and Horner4b in the late 1960s, after the discovery of Wilkinson’s homogeneous hydrogenation catalyst [RhCl(PPh3)3]. By replacing triphenylphosphine of the Wilkinson’s catalystwithresolvedchiralmonophosphines,6Knowles and Horner reported the earliest examples of enantioselective hydrogenation, albeit with poor enantioselectivity. Further exploration by Knowles with an improved monophosphine CAMP provided 88% ee in hydrogenation of dehydroamino acids.7 Later, two breakthroughs were made in asymmetric hydrogenation by Kagan and Knowles, respectively. Kagan reported the first bisphosphine ligand, DIOP, for Rhcatalyzed asymmetric hydrogenation.8 The successful application of DIOP resulted in several significant directions for ligand design in asymmetric hydrogenation. Chelating bisphosphorus ligands could lead to superior enantioselectivity compared to monodentate phosphines. Additionally, P-chiral phosphorus ligands were not necessary for achieving high enantioselectivity, and ligands with backbone chirality could also provide excellent ee’s in asymmetric hydrogenation. Furthermore, C2 symmetry was an important structural feature for developing new efficient chiral ligands. Kagan’s seminal work immediately led to the rapid development of chiral bisphosphorus ligands. Knowles made his significant discovery of a C2-symmetric chelating bisphosphine ligand, DIPAMP.9 Due to its high catalytic efficiency in Rh-catalyzed asymmetric hydrogenation of dehydroamino acids, DIPAMP was quickly employed in the industrial production of L-DOPA.10 The success of practical synthesis of L-DOPA via asymmetric hydrogenation constituted a milestone work and for this work Knowles was awarded the Nobel Prize in 2001.3k This work has enlightened chemists to realize * Corresponding author. 3029 Chem. Rev. 2003, 103, 3029−3069

1,995 citations

Journal ArticleDOI
Ulf Lindström1

1,477 citations

Journal ArticleDOI
TL;DR: An overview of the wide range of nanoreactors that have been constructed from synthetic and biological building blocks using both covalent and noncovalent approaches is given, starting from small organic molecular containers expanding to large compartment-containing assemblies.
Abstract: An overview of the wide range of nanoreactors that have been constructed from synthetic and biological building blocks using both covalent and noncovalent approaches is given. Focus is on self-assembled systems, varying in size from a few nanometers to tens of micrometers. The review is divided into several sections that cover the development of tailor-made nanoreactors, starting from small organic molecular containers expanding to large compartment-containing assemblies. First, the construction of capsules from low molecular weight compounds by means of covalent synthesis and self-assembly by highly directive and pre-designed interactions is discussed. Second, nanocapsules based on micellar and vesicular assemblies that are built up frow low molecular weight molecules are described. Finally, the construction of nanoreactors from macromolecular building blocks, as well as recent developments in the use of viruses as nanocontainers and reactors are outlined.

1,297 citations