- Rational Design of Thermodynamic and Kinetic Binding Profiles by Optimizing Surface Water Networks Coating Protein-Bound Ligands
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A previously studied congeneric series of thermolysin inhibitors addressing the solvent-accessible S2′ pocket with different hydrophobic substituents showed modulations of the surface water layers coating the protein-bound inhibitors. Increasing stabilization of water molecules resulted in an enthalpically more favorable binding signature, overall enhancing affinity. Based on this observation, we optimized the series by designing tailored P2′ substituents to improve and further stabilize the surface water network. MD simulations were applied to predict the putative water pattern around the bound ligands. Subsequently, the inhibitors were synthesized and characterized by high-resolution crystallography, microcalorimetry, and surface plasmon resonance. One of the designed inhibitors established the most pronounced water network of all inhibitors tested so far, composed of several fused water polygons, and showed 50-fold affinity enhancement with respect to the original methylated parent ligand. Notably, the inhibitor forming the most perfect water network also showed significantly prolonged residence time compared to the other tested inhibitors.
- Krimmer, Stefan G.,Cramer, Jonathan,Betz, Michael,Fridh, Veronica,Karlsson, Robert,Heine, Andreas,Klebe, Gerhard
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p. 10530 - 10548
(2016/12/16)
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- SPIROBENZYLAMINE-PHOSPHINE, PREPARATION METHOD THEREFOR AND USE THEREOF
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The present invention relates to a spirobenzylamine-phosphine, preparation method therefor and use thereof. The compound has a structure represented by formula (I), wherein n=0 to 3; R1, R2, R3, R4, R5, R6, R7, R8 and R9 having a value as defined in claim 1. Starting from the substituted 7-trifluoromesyloxy-7'-diarylphosphino-1, 1'-spiro-dihydroindene, the compound is synthesized in a two-step or three-step reactions. The new spirobenzylamine-phosphine is complexed with an iridium precursor and is subjected to ion exchange, to give an Iridium/spirobenzylamine-phosphine complex comprising various anions. The spiro benzyl amine-phosphine/Iridium complex according to the present invention may be used for catalyzing asymmetry hydrogenation of a variety of alpha-substituted acrylic acids, has high activity and enantio-selectivity, and has a good prospect of industrialization.
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Paragraph 0067
(2014/07/22)
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- Spirobenzylamine-Phosphine, Preparation Method Therefor And Use Thereof
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The present invention relates to a spirobenzylamine-phosphine, preparation method therefor and use thereof. The compound has a structure represented by formula (I), wherein n=0 to 3; R1, R2, R3, R4, R5, R6, R7, R8 and R9 having a value as defined in claim 1. Starting from the substituted 7-trifluoromesyloxy-7′-diarylphosphino-1,1′-spiro-dihydroindene, the compound is synthesized in a two-step or three-step reactions. The new spirobenzylamine-phosphine is complexed with an iridium precursor and is subjected to ion exchange, to give an Iridium/spirobenzylamine-phosphine complex comprising various anions. The spiro benzyl amine-phosphine/Iridium complex according to the present invention may be used for catalyzing asymmetry hydrogenation of a variety of alpha-substituted acrylic acids, has high activity and enantio-selectivity, and has a good prospect of industrialization.
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Paragraph 0078; 0079
(2014/07/22)
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- Iridium-catalyzed enantioselective hydrogenation of α,β- unsaturated carboxylic acids with tetrasubstituted olefins
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A highly efficient asymmetric hydrogenation of α,β-unsaturated carboxylic acids with tetrasubstituted olefin catalyzed by chiral spiro iridium complexes has been developed for the preparation of chiral α-substituted carboxylic acids in excellent enantioselectivities (up to 99% ee).
- Song, Song,Zhu, Shou-Fei,Li, Yu,Zhou, Qi-Lin
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supporting information
p. 3722 - 3725
(2013/08/23)
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- CHROMOBACTERIUM FORMULATIONS, COMPOSTIONS, METABOLITES AND THEIR USES
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Stabilized biological pesticides comprising Chromobacterium species, filtrate, supernatant, extract or pesticidally active substance derived therefrom with pesticidal activity having improved shelf life due to maintenance of physical uniformity and longer insecticide activity after use due to higher resistance to degradation when exposed to sunlight are disclosed.
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Page/Page column 26
(2013/05/21)
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- Efficient diastereoselective synthesis of (2R,3R,4R)-2-amino-3-hydroxy-4,5- dimethylhexanoic acid, the lactone linkage unit of homophymine A
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For the total synthesis of novel cyclodepsipeptide homophymine A, (2R,3R,4R)-2-amino-3-hydroxy-4,5- dimethylhexanoic acid was successfully synthesized by Evans' asymmetric alkylation and the anti-selective asymmetric hydrogenation of a chiral α-amino-β-keto ester as the key steps.
- Ohtaka, Junpei,Hamajima, Akinari,Nemoto, Tetsuhiro,Hamada, Yasumasa
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p. 245 - 250
(2013/03/28)
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- Enantioselective hydrogenation of α-substituted acrylic acids catalyzed by iridium complexes with chiral spiro aminophosphine ligands
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Highly active: Iridium complexes with chiral spiro aminophosphine ligands were synthesized and applied as catalysts for the asymmetric hydrogenation of α-substituted acrylic acids (see scheme). The complexes were highly active catalysts, showing turnover frequencies of up to 6000 h-1, and catalyst loadings could be reduced to 0.01 mol %. Copyright
- Zhu, Shou-Fei,Yu, Yan-Bo,Li, Shen,Wang, Li-Xin,Zhou, Qi-Lin
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supporting information; experimental part
p. 8872 - 8875
(2012/10/08)
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- Cu(I)-catalyzed, α-selective, allylic alkylation reactions between phosphorothioate esters and organomagnesium reagents
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Regiocontrol of allylic alkylation reactions involving hard nucleophiles remains a significant challenge and continues to be an active area of research. The lack of general methods in which α-alkylation is favored underscores the need for the development of new processes for achieving this type of selectivity. We report that Cu(I) catalyzes the allylic substitution of phosphorothioate esters with excellent α-regioselectivity, regardless of the nature of the Grignard reagent that is used. To the best of our knowledge, the Cu-catalyzed allylic alkylation of phosphorothioate esters has never been described. We have also developed a simple protocol for inducing high α selectivity starting from secondary allylic halides. This is accomplished by using sodium phosphorothioates as an additive.
- Lauer, Andrew M.,Mahmud, Farzeen,Wu, Jimmy
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experimental part
p. 9119 - 9123
(2011/08/04)
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- Enantioselective Friedel-Crafts reactions of ethenetricarboxylates and substituted pyrroles and furans and intramolecular reaction of benzene derivatives
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Compared to enantioselective Friedel-Crafts reactions of indoles, reactions of alkylidene malonates with monocyclic aromatic compounds generally proceed with low enantioselectivity. The Friedel-Crafts reactions of ethenetricarboxylates 1 and monocyclic heteroaromatic compounds, such as substituted pyrroles and furans were investigated. The reaction of 1 with 2,4-dimethylpyrrole in the presence of a chiral bisoxazoline-copper(II) complex (10 mol %) in tetrahydrofuran at room temperature gave alkylated products in up to 72% ee. The reaction of 1 with 2-substituted furans gave alkylated products in 46-62% ee. The absolute stereochemistry of the furan Friedel-Crafts product 7e was determined by transformation to the known 2,3-dimethylbutyric acid. The intramolecular reaction of benzene derivatives gave cyclized products up to 56% ee.
- Yamazaki, Shoko,Kashima, Shinichi,Kuriyama, Taiki,Iwata, Yuko,Morimoto, Tsumoru,Kakiuchi, Kiyomi
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experimental part
p. 1224 - 1234
(2009/10/24)
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- A cleavable linker strategy for optimising enolate alkylation reactions of a polymer-supported Evans' oxazolidin-2-one
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A cleavable linker strategy has been used to optimise the enolate alkylation reactions of a recyclable l-tyrosine derived polymer-supported oxazolidin-2-one for the asymmetric synthesis of a series of chiral α-alkyl acids. The Royal Society of Chemistry.
- Green, Rachel,Merritt, Andrew T.,Bull, Steven D.
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p. 508 - 510
(2008/09/20)
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- Highly diastereoselective preparation of (E)-alkenylsilanes bearing an α-chiral center
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(Chemical Equation Presented) The copper(I)-mediated anti-S N2′ allylic substitution allows a highly stereoselective preparation of alkenylsilanes bearing a chiral center in the α-position with high transfer of chirality. These alkenylsilanes were converted into α,β-unsaturated ketones or into the corresponding boronic esters without loss of the chiral information.
- Perrone, Sylvie,Knochel, Paul
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p. 1041 - 1044
(2008/02/01)
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- Highly efficient enantioselective synthesis of optically active carboxylic acids by Ru(OCOCH3)2[(S)-H8-BINAP]
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In the presence of a catalytic amount of Ru(OCOCH3)2[(S)-H8-BINAP] [H8-BINAP = 2,2′-bis-(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′- octahydro-1,1′-binaphthyl], the asymmetric hydrogenation of α,β- and β,γ-unsaturated carboxylic acids afforded the corresponding saturated carboxylic acids in higher enantiomeric excesses and at faster reaction rates than those using the Ru(OCOCH3)2[(R)-BINAP] catalyst [BINAP = 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl]. The hydrogenation of (E)-2-alkyl-2-alkenoic acids by the H8-BINAP catalyst system produced saturated acids in 95-97% ee. 2-Methylcinnamic acid was treated with H8-BINAP-Ru(II) complex as a catalyst to yield a hydrogenated product in much higher ee than that produced by BINAP-Ru(II) (89 and 30% ee, respectively). This homogeneous catalysis using H8-BINAP-Ru(II) established a promising synthetic route to (S)-ibuprofen in up to 97% ee. Asymmetric hydrogenation of β-disubstituted acrylic acids also proceeded smoothly with good enantioselectivities (70-93% ee). In addition, the hydrogenation of trisubstituted acrylic acids (up to 88% ee) was investigated. Hydrogen pressure effect on the sense and level of enantioselection was shown to be substrate dependent. The difference between the H8-BINAP- and BINAP-Ru(II) complexes was also discussed.
- Uemura, Toshitsugi,Zhang, Xiaoyoung,Matsumura, Kazuhiko,Sayo, Noboru,Kumobayashi, Hidenori,Ohta, Tetsuo,Nozaki, Kyoko,Takaya, Hidemasa
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p. 5510 - 5516
(2007/10/03)
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- Stereoselective addition of organometallic reagents to N-(tosyl)vinylsulfoximines
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Treatment of N-(toluene-p-sulfonyl)vinylsulfoximines 3 with methyllithium at -78°C, followed by addition of chlorotrimethylsilane, results in the efficient formation of α-silyl vinylsulfoximines 6 in good to excellent yield. Nucleophilic addition of a range of simple alkyl and aryl organometallics (lithium, copper-lithium and Grignard reagents) occurs in variable yield to give the Michael adducts 8 with organolithium reagents most effective. The degree of stereoselectivity of each of the addition reactions was determined by 1H NMR of the desilylated products 9, and proved to be synthetically useful for compounds in which the starting α-silylvinylsulfoximines were branched at the γ-position, and also when phenylhthium was used as the nucleophile. The sense of stereoselectivity was determined in two cases by X-ray crystal structure analyses (of 9e and 9i). A one-pot process for the conversion of α-silylvinylsulfoximines 6 to α-substituted carboxylic acids 11 was developed, using an in situ phenylselenation-oxidation process following the initial conjugate addition. Use of enantiomerically pure starting materials allowed the assignment of configuration of two carboxylic acids (13e and 13h) by comparison with literature data, and hence indirectly of the relative stereochemistry of the initial Michael adducts 9e and 9h.
- Jackson, Richard F. W.,Briggs, Andrew D.,Brown, Paul A.,Clegg, William,Elsegood, Mark R. J.,Frampton, Christopher
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p. 1673 - 1682
(2007/10/03)
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