473567-47-4Relevant academic research and scientific papers
MaxPHOS ligand: PH/NH tautomerism and rhodium-catalyzed asymmetric hydrogenations
Cristobal-Lecina, Edgar,Etayo, Pablo,Doran, Sean,Reves, Marc,Martin-Gago, Pablo,Grabulosa, Arnald,Costantino, Andrea R.,Vidal-Ferran, Anton,Riera, Antoni,Verdaguer, Xavier
, p. 795 - 804 (2014/04/03)
MaxPHOS is an active and robust P-stereogenic ligand for asymmetric catalysis. The presence of an -NH- bridge between the two phosphine moieties allows the NH/PH tautomerism to take place. The neutral ligand, in which the NH form predominates, is an air-sensitive compound. However, protonation of MaxPHOS leads to the stable PH form of the ligand, in which the overall positive charge is distributed on both P centers. This protonation turns the MaxPHOS×HBF4 salt 3 into an air-stable compound both in the solid state and in solution. The salt 3 is also a convenient precursor for the preparation of rhodium(I) complexes by direct ligand exchange with the complex [Rh(acac)(cod)]. Finally, the corresponding rhodium(I)-MaxPHOS complex was tested in the asymmetric hydrogenation of a wide range of substrates. The complex proved to be a highly selective and robust system in these reactions.
Evidence for the role of tetramethylethylenediamine in aqueous negishi cross-coupling: Synthesis of nonproteinogenic phenylalanine derivatives on water
Ross, Andrew J.,Dreiocker, Frank,Schae Fer, Mathias,Oomens, Jos,Meijer, Anthony J.H.M.,Pickup, Barry T.,Jackson, Richard F.W.
experimental part, p. 1727 - 1734 (2011/05/30)
The structure of the alkylzinc-tetramethylethylenediamine (TMEDA) cluster cation 3 has been determined in the gas phase by a combination of tandem mass spectrometry, infrared multiphoton dissociation (IRMPD) spectroscopy, and DFT calculations. Both sets of experimental results establish the existence of a strongly stabilizing interaction of TMEDA with the zinc cation. High-level DFT calculations on the alkylzinc-TMEDA cluster cation 3 allowed the identification of two low energy conformers, each featuring a four-coordinate zinc atom with a bidentate TMEDA ligand, and internal coordination from the carbonyl group of the Boc group to zinc. The experimental IRMPD spectrum is reproduced with an appropriately weighted combination of the IR spectra of the two conformers identified by theory. DFT calculations on the structure of the alkylzinc halide 2 with coordinated TMEDA using the PCM model of water solvent suggest that TMEDA can promote ionization of the zinc-iodine bond in organozinc iodides under aqueous conditions, providing a credible explanation for the role of TMEDA in stabilizing the carbon-zinc bond. Reaction of the serine-derived iodide 1 with aryl iodides "on water", promoted by nano zinc in the presence of PdCl2 (Amphos) 2 (5 mol %) and TMEDA, leads to the formation of protected phenylalanine derivatives 4 in reasonable yields. In the case of ortho-substituted aryl iodides and aryl iodides that are solids at room temperature, conducting the reaction at 65°C gives improved results. In all cases, the product 5 of reductive dimerization of the iodide 1 is also isolated.
BETA-SECRETASE INHIBITING COMPOUNDS HAVING OXO-DIHYDRO-PYRAZOLE MOIETY
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Page/Page column 35, (2009/04/25)
Disclosed are compounds represented by Formula (I) as defined in the specification, or pharmaceutically acceptable salts or isomers thereof, and a pharmaceutical composition for inhibiting beta-secretase activity comprising a therapeutically effective amo
BETA-SECRETASE INHIBITING COMPOUNDS
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Page/Page column 56, (2009/04/25)
Disclosed are compounds represented by Formula (I) as defined in the specification, or pharmaceutically acceptable salts or isomers thereof, and a pharmaceutical composition for inhibiting beta-secretase activity comprising a therapeutically effective amount of the same.
Synthesis, SAR, and X-ray structure of human BACE-1 inhibitors with cyclic urea derivatives
Park, Heuisul,Min, Kyeongsik,Kwak, Hyo-Shin,Koo, Ki Dong,Lim, Dongchul,Seo, Sang-Won,Choi, Jae-Ung,Platt, Bettina,Choi, Deog-Young
, p. 2900 - 2904 (2008/12/22)
We describe synthesis and evaluation of a series of cyclic urea derivatives with hydroxylethylamine isostere. Modification of P3, P1, and P2′ and combination of SAR display a >100-fold increase in potency with good cellular activity (IC50 = 0.1
Methods of treatment of amyloidosis using bi-aryl aspartyl protease inhibitors
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Page/Page column 42, (2010/02/15)
The invention relates to novel compounds and methods of treating diseases, disorders, and conditions associated with amyloidosis. Amyloidosis refers to a collection of diseases, disorders, and conditions associated with abnormal deposition of A-beta protein.
SUBSTITUTED HYDROXYETHYLAMINE ASPARTYL PROTEASE INHIBITORS
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Page/Page column 159-160, (2008/06/13)
The invention relates to novel compounds and also to methods of treating at least one disease, disorder, or condition associated with amyloidosis using such compounds. Amyloidosis refers to a collection of diseases, disorders, and conditions associated with abnormal deposition of A-beta protein.
METHODS OF TREATMENT OF AMYLOIDOSIS USING ASPARTYL-PROTEASE INHIBITORS
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Page/Page column 192, (2010/02/13)
The invention relates to acetyl 2-hydroxy-1,3-diaminospirocyclohexanes and derivatives thereof that are useful in treating diseases, disorders, and conditions associated with amyloidosis. Amyloidosis refers to a collection of diseases, disorders, and conditions associated with abnormal deposition of A-beta protein.
METHODS OF TREATMENT OF AMYLOIDOSIS USING BI-CYCLIC ASPARTYL PROTEASE INHIBITORS
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Page/Page column 291-292, (2010/02/14)
The invention relates to novel compounds and methods of treating diseases, disorders, and conditions associated with amyloidosis. Amyloidosis refers to a collection of diseases, disorders, and conditions associated with abnormal deposition of A-beta protein.
SUBSTITUTED HYDROXYETHYLAMINE ASPARTYL PROTEASE INHIBITORS
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Page/Page column 105-106, (2010/02/14)
The invention relates to novel compounds and also to methods of treating at least one disease, disorder, or condition associated with amyloidosis using such compounds. Amyloidosis refers to a collection of diseases, disorders, and conditions associated with abnormal deposition of A-beta protein.
