39599-89-8Relevant academic research and scientific papers
SPIRO-1,1'-BIINDANE-7,7-BISPHOSPHINE OXIDES AS HIGHLY ACTIVE SUPPORTING LIGANDS FOR PALLADIUM-CATALYZED ASYMMETRIC HECK REACTION
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Page/Page column 52, (2015/01/06)
The present invention relates to catalyst complexes comprising palladium (Pd) and at least one spiro-1,1 '-biindane-7,7'- bisphosphine oxide ligand as disclosed herein, and their use. The present invention is further directed to the asymmetric Pd-catalyzed covalent carbon-carbon single bond formation from aryl, heteroaryl and alkenyl triflates and halides and olefins utilising the said catalyst complexes.
Rational design of cyclopropane-based chiral PHOX ligands for intermolecular asymmetric Heck reaction
Rubina, Marina,Sherrill, William M.,Barkov, Alexey Yu.,Rubin, Michael
, p. 1536 - 1548 (2014/07/22)
A novel class of chiral phosphanyl-oxazoline (PHOX) ligands with a conformationally rigid cyclopropyl backbone was synthesized and tested in the intermolecular asymmetric Heck reaction. Mechanistic modelling and crystallographic studies were used to predict the optimal ligand structure and helped to design a very efficient and highly selective catalytic system. Employment of the optimized ligands in the asymmetric arylation of cyclic olefins allowed for achieving high enantioselectivities and significantly suppressing product isomerization. Factors affecting the selectivity and the rate of the isomerization were identified. It was shown that the nature of this isomerization is different from that demonstrated previously using chiral diphosphine ligands.
Design, synthesis and structure-activity relationship of novel [3.3.1] bicyclic sulfonamide-pyrazoles as potent γ-secretase inhibitors
Aubele, Danielle L.,Truong, Anh P.,Dressen, Darren B.,Probst, Gary D.,Bowers, Simeon,Mattson, Matthew N.,Semko, Chris M.,Sun, Minghua,Garofalo, Albert W.,Konradi, Andrei W.,Sham, Hing L.,Zmolek, Wes,Wong, Karina,Goldbach, Erich,Quinn, Kevin P.,Sauer, John-Michael,Brigham, Elizabeth F.,Wallace, William,Nguyen, Lan,Bova, Michael P.,Hemphill, Susanna S.,Basi, Guriqbal
scheme or table, p. 5791 - 5794 (2011/10/19)
The structure-activity relationship (SAR) of a novel, potent and metabolically stable series of sulfonamide-pyrazoles that attenuate β-amyloid peptide synthesis via γ-secretase inhibition is detailed herein. Sulfonamide-pyrazoles that are efficacious in reducing the cortical Aβx-40 levels in FVB mice via a single PO dose, as well as sulfonamide-pyrazoles that exhibit selectivity for inhibition of APP versus Notch processing by γ-secretase, are highlighted.
BINAP versus BINAP(O) in asymmetric intermolecular Mizoroki-Heck reactions: Substantial effects on selectivities
Woeste, Thorsten H.,Oestreich, Martin
experimental part, p. 11914 - 11918 (2011/11/29)
2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) was employed as chiral ligand in the enantioselective intermolecular Mizoroki-Heck reaction, whereas the use of cognate BINAP(O) (monooxidized BINAP) is unprecedented. The regio- and enantioselectivity of the arylation of representative cyclic alkenes changes dramatically in the presence of hemilabile BINAP(O) instead of BINAP. The arylation of 2,3-dihydrofuran is perfectly regiodivergent (98:2 versus 0:100) and the arylation of cyclopentene is only enantioselective with BINAP(O) [60 versus 10% enantiomeric excess (ee)]. Use of [Pd2(dba)3]·dba (dba=dibenzylideneacetone) instead of Pd(OAc)2 produces as high as 86% ee in the arylation of cyclopentene.
Biaryl phosphite-oxazoline ligands from the chiral pool: Highly efficient modular ligands for the asymmetric Pd-catalyzed heck reaction
Mazuela, Javier,Pamies, Oscar,Dieguez, Montserrat
experimental part, p. 3434 - 3440 (2010/06/21)
A highly modular library of readily available phosphite-oxazoline ligands L1-L21a-g was successfully applied in the asymmetric Pd-catalyzed Heck reactions of several substrates and triflates under thermal and microwave conditions. This ligand library cont
Screening of a modular sugar-based phosphite-oxazoline ligand library in asymmetric Pd-catalyzed Heck reactions
Mata, Yvette,Pàmies, Oscar,Diéguez, Montserrat
, p. 3296 - 3304 (2008/01/06)
We have synthesised a library of phosphite-oxazoline ligands derived from readily available D-glucosamine. These ligands have been successfully screened in the palladium-catalysed Heck reaction of several substrates with high regio- (up to 99%) and enanti
Preparation of 4-arylcyclopentenes by sequential diallylation of arylaldehydes and ring-closing metathesis
Durand, Anne-Catherine,Brahmi, Lamia,Lahrech, Mokhtar,Hacini, Salih,Santelli, Maurice
, p. 1825 - 1833 (2007/10/03)
Allylsilane diallylation of aryl aldehydes followed by ring closure metathesis leads to 4-arylcyclopentenes in good yields. Copyright Taylor & Francis, Inc.
Chiral phosphite-oxazolines: A new class of ligands for asymmetric Heck reactions
Mata, Yvette,Dieguez, Montserrat,Pamies, Oscar,Claver, Carmen
, p. 5597 - 5599 (2007/10/03)
(Chemical Equation Presented) A series of phosphite-oxazoline ligands, derived from readily available D-glucosamine, have been used for the first time in the palladium-catalyzed Heck reaction of several substrates with high regio- and enantioselectivities (ee's up to 99%) and improved activities in standard conditions.
Chiral bidentate (phosphinophenyl)benzoxazine ligands in asymmetric catalysis
Bernardinelli, Gerald H.,Kuendig, E. Peter,Meier, Peter,Pfaltz, Andreas,Radkowski, Karin,Zimmermann, Nicole,Neuburger-Zehnder, Margareta
, p. 3233 - 3246 (2007/10/03)
The new chiral bidentate (phosphinoaryl)benzoxazine ligands 2 were applied in asymmetric catalysis, Rhodium and copper complexes catalyzed the hydrosilylation of acetophenone and [4 + 2] cycloadditions with moderate enantioselectivity. Iridium complexes were used to hyrogenate di-, tri-, and tetrasubstituted alkenes, giving products with moderate to high enantiomer excesses. Enantioselective allylic substitution and Heck reactions catalyzed by [(phosphinoaryl)benzoxazine]palladium complexes occurred with high enantioselectivities. The results were similar to those obtained with the corresponding dihydro(phosphinoaryl)oxazole ligands. Comparison of the structures of (diphenylallyl)(benzoxazine)palladium and (diphenylallyl)(dihydrooxazole)-palladium complexes showed that the coordination geometries and the chiral environments of the metal centers are very similar, which explains why the enantioselectivities induced by the two ligand classes are in the same range.
Chiral P,N-ligands based on ketopinic acid in the asymmetric heck reaction
Gilbertson, Scott R.,Fu, Zice
, p. 161 - 164 (2007/10/03)
equation presented Novel chiral P,N-ligands were synthesized from (1S)-(+)-ketopinic acid using palladium-catalyzed coupling reaction of a vinyl triflate and either a diarylphosphine or a dialkylphosphine as the key step. Palladium complexes of these ligands are efficient catalysts for asymmetric Heck reaction between aryl or alkenyl triflates and cyclic alkenes. Products were obtained with good to excellent enantioselectivity from arylation and alkenylation of 1,2-dihydrofuran, cyclopentene, and 4,7-dihydro-1,3-dioxepin.
