- Achmatowicz rearrangement enables hydrogenolysis-free gas-phase synthesis of pentane-1,2,5-triol from furfuryl alcohol
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Highly efficient synthesis of pentane-1,2,5 triol, a promising member of biorenewable C5 alcohols, has been achieved by gas-phase hydrogenation of the Achmatowicz intermediate derived from furfuryl alcohol. The hydrogenation was carried out on monocomponent or bicomponent Ni and/or Pt modified mesoporous silica catalysts. The process features the absence of hydrogenolysis of the furan ring and rendered 100% selectivity together with additional green chemistry benefits, such as mild and simpler solvent free technology that operates at atmospheric pressure. The bicomponent Ni/Pt modified mesoporous silica catalysts exhibited the highest catalytic activity, with 10Ni1Pt/KIT-6 being the most active, providing up to 100% conversion.
- Simeonov, Svilen P.,Lazarova, Hristina I.,Marinova, Maya K.,Popova, Margarita D.
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- Biocatalytic approaches to both enantiomers of (2R*,3S*)-2-allyloxy-3,4,5,6-tetrahydro-2H-pyran-3-ol
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Both enantiomers of (2R*,3S*)-2-allyloxy-3,4,5,6-tetrahydro-2H-pyran-3-ol, a precursor of chiral auxiliary for asymmetric addition of organometallics, and its analog, (2S,3S)-2-ethoxy-3,4,5,6-tetrahydro-2H-pyran-3-ol were prepared by biocatalytic optical resolutions. Lipase-catalyzed enantioselective acetylation of the racemate in organic solvent worked well with a high enantioseleclivity. Pseudomonas cepacia lipase was most effective (E = 11-17) for the kinetic resolution. Under the optimized condition, the products, (2R,3S)-2-allyloxy-3,4,5,6-tetrahydro-2H-pyran-3-ol and (2S,3S)-2-ethoxy analog with more than 97% e.e. were obtained in 31-45% yield with 52-62% conversion. The enantiomer, (2S,3R)-2-allyloxy compound was secured by two ways. The repetition of the lipase-catalyzed acetylation on partially enantiomerically enriched substrate afforded the acetate with a high e.e. (97%). A newly developed double resolution procedure in one-pot reaction was also successful. In this case, the apparent E value via two steps became as high as 71.Copyright
- Sugai, Takeshi,Ikeda, Hajime,Ohta, Hiromichi
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- Selective hydrogenolysis of benzyl ethers in the presence of benzylidene acetals with Raney nickel
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A simple method to remove selectively a benzyl group protecting a hydroxyl function in the presence of a benzylidene acetal by catalytic hydrogenolysis with Raney nickel is reported. This method was successfully applied to the synthesis of the C1-C14 fragment of dolabelides.
- Vincent, Aurélie,Prunet, Jo?lle
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- Biorefinery via Achmatowicz Rearrangement: Synthesis of Pentane-1,2,5-triol from Furfuryl Alcohol
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A new scalable synthesis of pentane-1,2,5-triol from the furanics platform has been developed. Excellent yields of up to 92 % are obtained under flow conditions by using readily available catalysts from the existing pool. The strategy exploits the highly functionalized Achmatowicz product as a key intermediate, thus circumventing problems related to the low reactivity of the parent furfural and furfuryl alcohol. Besides expanding the portfolio of biomass-derived C5 alcohols, this strategy may also be further applied for the establishment of a versatile bio-based chemical platform.
- Simeonov, Svilen P.,Ravutsov, Martin A.,Mihovilovic, Marko D.
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- Adsorption Configuration-Determined Selective Hydrogenative Ring Opening and Ring Rearrangement of Furfural over Metal Phosphate
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Developing an economic catalyst to upgrade furfural to alcohols (such as linear alcohol and cyclopentanol) is highly significant for fine chemical synthesis and biomass utilization. Here, a class of metal phosphate nanoparticles (such as CoP, Co2P, and Ni2P) with different metal compositions and topological structures is synthesized. The acidity and hydrogen activation ability were well adjusted according to the types. An 80.2% yield of 1,2,5-pentanetriol was reported for the first time via a hydrogenative ring-opening route over CoP, whereas Ni2P shows a high catalytic efficiency for cyclopentanol with a 62.8% yield via a hydrogenative ring-rearrangement route. Based on the catalytic performance of Pd/C and the result of attenuated total reflectance-infrared spectroscopy, the route difference is derived from the adsorption configuration of furfural on the catalyst. After loading on the insert support, the metal phosphate/support catalysts show high activity and stability during the recycling experiments. This work provides an effective strategy to regulate the reaction path through an adsorption mechanism and shows the precise synergistic effect of hydrogenation and acid catalysis.
- Tong, Zhikun,Li, Xiang,Dong, Jingyu,Gao, Rui,Deng, Qiang,Wang, Jun,Zeng, Zheling,Zou, Ji-Jun,Deng, Shuguang
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- Hydrodeoxygenation of C4-C6 sugar alcohols to diols or mono-alcohols with the retention of the carbon chain over a silica-supported tungsten oxide-modified platinum catalyst
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The hydrodeoxygenation of erythritol, xylitol, and sorbitol was investigated over a Pt-WOx/SiO2 (4 wt% Pt, W/Pt = 0.25, molar ratio) catalyst. 1,4-Butanediol can be selectively produced with 51% yield (carbon based) by erythritol hydrodeoxygenation at 413 K, based on the selectivity over this catalyst toward the regioselective removal of the C-O bond in the -O-C-CH2OH structure. Because the catalyst is also active in the hydrodeoxygenation of other polyols to some extent but much less active in that of mono-alcohols, at higher temperature (453 K), mono-alcohols can be produced from sugar alcohols. A good total yield (59%) of pentanols can be obtained from xylitol, which is mainly converted to C2 + C3 products in the literature hydrogenolysis systems. It can be applied to the hydrodeoxygenation of other sugar alcohols to mono-alcohols with high yields as well, such as erythritol to butanols (74%) and sorbitol to hexanols (59%) with very small amounts of C-C bond cleavage products. The active site is suggested to be the Pt-WOx interfacial site, which is supported by the reaction and characterization results (TEM and XAFS). WOx/SiO2 selectively catalyzed the dehydration of xylitol to 1,4-anhydroxylitol, whereas Pt-WOx/SiO2 promoted the transformation of xylitol to pentanols with 1,3,5-pentanetriol as the main intermediate. Pre-calcination of the reused catalyst at 573 K is important to prevent coke formation and to improve the reusability.
- Betchaku, Mii,Cao, Ji,Liu, Lujie,Nakagawa, Yoshinao,Tamura, Masazumi,Tomishige, Keiichi,Yabushita, Mizuho
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supporting information
p. 5665 - 5679
(2021/08/16)
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- Method for converting furfural into 1, 2, 5-pentanetriol through hydrogenation hydrolysis
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The invention discloses a method for converting furfural into 1, 2, 5-pentanetriol through hydrogenation hydrolysis, and belongs to the field of fine organic chemicals. The method comprises the following steps: adding different metal phosphides or metal phosphides loaded with different carriers into a mixture of furfural and water as a catalyst, and performing reacting in a hydrogen atmosphere toobtain 1, 2, 5-pentanetriol. The invention discloses a novel method for preparing 1, 2, 5-pentanetriol by taking a biomass platform compound furfural as a raw material, which is simple in technological process, convenient to operate and mild in reaction condition, a catalyst can be separated and recycled, the production cost is reduced, and the method has a good application prospect.
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Paragraph 0020-0043
(2021/01/04)
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- C?O Hydrogenolysis of Tetrahydrofurfuryl Alcohol to 1,5-Pentanediol Over Bi-functional Nickel-Tungsten Catalysts
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In this study, we report a series of bimetallic Ni?WOx catalyst for the ring-opening of THFA into 15PDO. The structure-performance relationship of the catalysts was discussed based on extensive characterization using techniques such as BET, H2-TPR, NH3-TPD, Pyr-IR, IPA-TPD-MS, XRD, XPS and EXAFS/XANES. The acidity measurements show that higher W density leads to the higher amount of acid density, which could be assigned to the creation of Lewis acid sites mainly on the surface of the calcined catalysts. H2-TPR profiles of Ni?WOx catalysts show that there is a strong interaction between Ni and W species, enhancing the reducibility of WOx. XRD measurements of calcined Ni?WOx catalysts reveal that the dispersion of Ni particles is enhanced after addition of WOx species. After reduction, different peaks corresponding to metallic Ni and WO3?x are identified for 10Ni?WOx catalysts, as well as new peak assigned to Ni?W intermetallic phase on 10Ni?30WOx catalyst. The formation of Ni?W intermetallic phase was further proved using XPS and EXAFS studies. THFA hydrogenolysis was also conducted under aqueous-phase conditions over Ni?WOx catalysts, yielding up to 47 % selectivity to 15PDO, along with a highest combined C5 polyols (i. e., 15PDO and 125PTO) selectivity of approximately 64 %. However, the Ni?WOx catalytic system suffers from deactivation process due to the hydrothermal dissolution of the active phase. Further investigation reveals the better stability of metallic tungsten and Ni?W intermetallic phase (Ni4W) against leaching since their corresponding peaks in the XRD patterns of spent catalysts remains nearly unchanged. Finally, 1,4-dioxane as an organic solvent was employed in THFA hydrogenolysis reaction, resulting in different product distribution, with a THP yield of around 54 %. The catalyst crystalline structure is preserved because of very low Ni and W leaching when 1,4-dioxane is used as solvent.
- Soghrati, Elmira,Kok Poh, Chee,Du, Yonghua,Gao, Feng,Kawi, Sibudjing,Borgna, Armando
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p. 4652 - 4664
(2018/10/02)
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- Mechanistic study on -C-O- and -C-C- hydrogenolysis over Cu catalysts: Identification of reaction pathways and key intermediates
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Important petro-based polyol compounds with a longer carbon chain, such as oligohydroxy hexanes (e.g. 1,2- and 1,6-hexanediol or 1,2,6-hexanetriol), require at least three to four synthesis steps. Replacing this complex chemistry by a one-pot reaction via -C-O- bond cleavage from sugars would be a significant breakthrough for the use of renewable feedstocks. Cu is known for its dehydroxylation (deoxygenation) properties, yielding the desired products from sugars. In this joint research between academic and industrial chemistry, we have identified so far unknown intermediate products and present the first mechanism that explains the selective cleavage of OH-groups over copper. Strong interactions between polyols, unsaturated species and the copper surface are observed. Stable five-membered rings are formed with Cu via two vicinal OH-groups of the polyol reactant that makes these OH-groups inert to -C-O- bond cleavage. Adjacent free OH-groups in close proximity to the catalyst are dehydroxylated (deoxygenated). We further show that degradation of polyols not only occurs via commonly cited retro-aldol reactions. The formation of acid intermediates with subsequent decarboxylation is validated as a new pathway for -C-C- bond cleavage to short-chain polyols and CO2. The proposed mechanisms for -C-O- and -C-C- bond cleavage elucidate why hydrogenolysis reactions require high hydrogen pressure (up to 200 bar) to suppress the degradation of sugars and obtain high yields of deoxy C6 products. With this knowledge, the improvement of a standard commercial Cu-RANEY catalyst under optimized reaction conditions was shown. In contrast to alumina-supported Cu, the Cu-Al alloy in a RANEY-type catalyst shows selective -C-O- bond cleavage properties while maintaining the C6 carbon chain. These new insights into the transformation of sugars to value added commodities show the potential for new approaches in future biorefinery concepts.
- Kühne, Benjamin,Vogel, Herbert,Meusinger, Reinhard,Kunz, Sebastian,Kunz, Markwart
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p. 755 - 767
(2018/02/14)
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- Identification of a Water-Soluble Indirubin Derivative as Potent Inhibitor of Insulin-like Growth Factor 1 Receptor through Structural Modification of the Parent Natural Molecule
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Indirubins have been identified as potent ATP-competitive protein kinase inhibitors. Structural modifications in the 5-and 3′-position have been extensively investigated, but the impact of substituents in 5′-position is not equally well-studied. Here, we report the synthesis of new indirubin 3′-and 5′-derivatives in the search of water-soluble indirubins by introducing basic centers. Antiproliferative activity of all compounds in tumor cells was evaluated along with kinase inhibition of selected compounds. The results show the 3′-position to tolerate large substituents without compromising activity, whereas bulk and rigid substituents in 5′-position appear unfavorable. Screening molecular targets of water-soluble 3′-oxime ethers revealed 6ha as preferential inhibitor of insulin-like growth factor 1 receptor (IGF-1R) in a panel of 22 protein kinases and in cells. Consistently, 6ha inhibited tumor cell growth in the NCI 60 cell line panel and induced apoptosis. The results indicate that the 5′-position provides limited space for chemical modifications and identify 6ha as a potent water-soluble indirubin-based IGF-1R inhibitor.
- Cheng, Xinlai,Merz, Karl-Heinz,Vatter, Sandra,Zeller, Jochen,Muehlbeyer, Stephan,Thommet, Andrea,Christ, Jochen,W?lfl, Stefan,Eisenbrand, Gerhard
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p. 4949 - 4962
(2017/06/28)
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- Performance and characterization of rhenium-modified Rh-Ir alloy catalyst for one-pot conversion of furfural into 1,5-pentanediol
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One-pot selective conversion of highly concentrated furfural to 1,5-pentanediol (1,5-PeD) was carried out over Rh-added Ir-ReO x/SiO2 catalysts through two-step reaction temperatures. Over the optimized catalyst, Rh(0.66 wt%)-Ir-ReOx/SiO2, the maximum yield of 1,5-PeD was 71.1% from highly concentrated furfural (50 wt%) and 78.2% from diluted furfural (10 wt%). These values were higher than those obtained with Ir-ReOx/SiO2 or Pd-Ir-ReO x/SiO2 catalysts. Rh-Ir-ReOx/SiO2 showed much higher activity in the hydrogenation of furfural to tetrahydrofurfuryl alcohol intermediate in the low temperature step than Ir-ReOx/SiO2, although the hydrogenation activity was lower than that of Pd-Ir-ReOx/SiO2. A long reaction time in the low temperature step is necessary to obtain a good 1,5-PeD yield over Rh-Ir-ReOx/SiO2 in two-step reaction of furfural. The hydrogenolysis activity of Rh-Ir-ReOx/SiO2 for tetrahydrofurfuryl alcohol to 1,5-PeD in the high temperature step was higher than that of Pd-Ir-ReOx/SiO2 and was comparable to that of Ir-ReOx/SiO2. The characterization results of TPR, XRD, XANES, EXAFS, STEM-EDX and FT-IR of adsorbed CO indicated that Rh-Ir-ReO x/SiO2 catalysts showed the structure of Ir-Rh alloy particles partially covered with ReOx species. The hydrogenation activity of Rh-Ir-ReOx/SiO2 for the furan ring was higher than those of the mixture of Rh-Ir/SiO2 and Ir-ReO x/SiO2 or the mixture of Rh-ReOx/SiO 2 and Ir-ReOx/SiO2. Both Ir-Rh alloy formation and ReOx modification of alloy particles are essential for the high hydrogenation activity.
- Liu, Sibao,Amada, Yasushi,Tamura, Masazumi,Nakagawa, Yoshinao,Tomishige, Keiichi
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p. 2535 - 2549
(2014/07/22)
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- Selective hydrogenolysis of biomass-derived xylitol to ethylene glycol and propylene glycol on Ni/C and basic oxide-promoted Ni/C catalysts
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The selective hydrogenolysis of xylitol to ethylene glycol and propylene glycol was examined on Ni/C catalysts in the presence of solid bases, e.g. Ca(OH)2 and CeO2, physically mixed with or co-supported with Ni on C. Compared with Ru/C, the Ni/C catalysts were more selective to the two target glycols under identical conditions, apparently as a result of their lower hydrogenation activity and consequently favored the CC cleavage of xylose intermediate by the base catalyst over its competitive hydrogenation on the Ni particles. Noticeably, the presence of the solid bases rendered the Ni particles resistant to leaching and sintering, and thus stable in the xylitol hydrogenolysis. Supporting the solid bases, especially CeO2 and CaO, with the Ni particles on C led not only to a reduction in the amount of solid bases required, but also efficient formation of the two glycols with negligible lactic acid. For instance, on Ni-CaO/C (at a CaO/Ni molar ratio of 0.66), the combined selectivity to ethylene glycol and propylene glycol, together with glycerol, reached 69.5% at nearly 100% xylitol conversion at 473 K, 4.0 MPa H2. These features of the basic oxide-promoted Ni catalysts show their promising advantages over the noble Ru catalysts, upon optimization of their compositions and structures, and the reaction parameters, for the efficient hydrogenolysis of xylitol and other lignocellulose-derived polyols to produce the two target glycols.
- Sun, Jiying,Liu, Haichao
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- IMPROVED CATIONIC LIPIDS AND METHODS FOR THE DELIVERY OF THERAPEUTIC AGENTS
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The present invention provides compositions and methods for the delivery of therapeutic agents to cells. In particular, these include novel cationic lipids and nucleic acid-lipid particles that provide efficient encapsulation of nucleic acids and efficient delivery of the encapsulated nucleic acid to cells in vivo. The compositions of the present invention are highly potent, thereby allowing effective knock-down of a specific target protein at relatively low doses. In addition, the compositions and methods of the present invention are less toxic and provide a greater therapeutic index compared to compositions and methods previously known in the art.
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Page/Page column 163
(2011/02/24)
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- IMPROVED AMINO LIPIDS AND METHODS FOR THE DELIVERY OF NUCLEIC ACIDS
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The present invention provides superior compositions and methods for the delivery of therapeutic agents to cells. In particular, these include novel lipids and nucleic acid-lipid particles that provide efficient encapsulation of nucleic acids and efficient delivery of the encapsulated nucleic acid to cells in vivo. The compositions of the present invention are highly potent, thereby allowing effective knock-down of specific target proteins at relatively low doses. In addition, the compositions and methods of the present invention are less toxic and provide a greater therapeutic index compared to compositions and methods previously known in the art.
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Page/Page column 93
(2010/04/28)
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- Thermodynamic equilibria between polyalcohols and cyclic ethers in high-temperature liquid water
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Thermodynamic equilibrium constants between polyalcohols and cyclic ethers in water at 573 K were determined by measuring their concentrations after the long-term reaction in a batch reactor. Intramolecular dehydration reactions of polyalcohols were important for conversion of biomass-derived carbohydrates; however, the yields of products were limited by thermodynamic equilibria between polyalcohols and products. All the thermodynamic equilibrium constants were estimated by the long-term dehydration reaction of 1 mol ·dm-3 polyalcohol aqueous solutions at 573 K. The thermodynamic equilibrium constants between butanepolyols or pentanepolyols and five-membered or six-membered cyclic ethers were within a range from (39 to 337) mol ·dm-3.
- Yamaguchi, Aritomo,Hiyoshi, Norihito,Sato, Osamu,Bando, Kyoko K.,Masuda, Yoshio,Shirai, Masayuki
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experimental part
p. 2666 - 2668
(2010/07/08)
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- Unexpected tosyl deprotection during osmium catalysed dihydroxylation
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Depending on the double bond position, tosyl deprotection was observed during olefin dihydroxylation using osmium tetroxide, leading to triols.
- Batt, Frédéric,Piva, Olivier,Fache, Fabienne
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p. 566 - 568
(2008/04/13)
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- 4-(tert-Butyldimethylsilyloxy)benzylidene acetal: A novel benzylidene-type protecting group for 1,2-diols
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A novel 1,2-diol-protecting group, p-silyloxybenzylidene group, has been developed. In addition to the stepwise deprotection conditions including desilylation and the subsequent acidic hydrolysis of the p-hydroxybenzylidene group in AcOH-THF-H2O, we have established the one-pot deprotection under basic conditions [K2CO3 (5equiv), NH 2OH·HCl (5equiv), and CsF (1equiv) in MeOH-H2O].
- Kaburagi, Yosuke,Osajima, Hiroyuki,Shimada, Kousei,Tokuyama, Hidetoshi,Fukuyama, Tohru
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p. 3817 - 3821
(2007/10/03)
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- Preparation of N-substituted-hydroxycycloalkylamine derivatives
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A process for the preparation of N-substituted-hydroxycycloalkylamine derivatives, that are useful intermediates for the synthesis of various organic chemicals including pharmaceutical and agrochemical compounds, represented by formula (1), by reacting a 1,2-dihydroxalkyl alcohol, represented by the following formula (2), with a thionyl halide to produce an intermediate 1,2-cyclosulfinylalkyl halide represented by the following formula (3); and then cyclizing that intermediate with an amine compounds represented by the following formula (4). In the above structural formuli, * represents an asymmetric carbon atom; R1is hydrogen or an amino-protecting group; m is an integer of 1-3; and X is halogen. The reactant compounds as well as the compounds made according to this invention have the following substitution pattern: n=1, R2=OH, R3=H and m=1; n=1, R2=H, R3=CH2OH and m=2; n=2, R2=OH, R3=H; and m=2; and n=2, R2=H, R3=CH2OH and m=3.
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- A synthesis of (-)-tashiromine and formal synthesis of (+)-tashiromine utilizing a highly enantioselective pyrrole/cobaloxime π-cation cyclization
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Cyclization of (5-N-pyrrolyl-2-hydroxypentyl)cobaloxime (13) proceeds by intramolecular electrophilic aromatic substitution of a cobaloxime π-cation onto the pyrrole ring to provide 6-exo cyclization product (14) in 95% yield. This cyclization is highly enantioselective. It is applied to a synthesis of highly enantioenriched (-)-tashiromine, (-)-21, and a formal synthesis of (+)-tashiromine.
- Gage, Jennifer L.,Branchaud, Bruce P.
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p. 7007 - 7010
(2007/10/03)
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- 'Active' conformation of the inositol monophosphatase substrate, adenosine 2'-phosphate: role of the ribofuranosyl O-atoms in chelating a second Mg2+ ion
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In the presence of Mg2+ ions, inositol monophosphatase from bovine brain catalyses the hydrolysis of the phosphate ester of a range of purine- and pyrimidine-containing nucleoside 2'-phosphates including adenosine 2'-phosphate (2'-AMP) but not adenosine 2'-phosphorothioate (2'-AMPS). 2'-AMPS also fails to serve as an inhibitor under these conditions.In contrast to the situation for the alcohol hydrolysis product, inositol, adenosine does not serve as a product inhibitor for the enzyme or mediate the enzyme-catalysed exchange of 18O-label from water into inorganic phosphate.However, in the presence of Mn2+ ions 2'-AMPS is a substrate for the enzyme.These findings indicate that the product adenosine does not bind to the enzyme in its ground-state conformations and that a strong phosphate group-holoenzyme interaction is required to stabilise a high-energy arrangement in the enzyme-substrate complexes of 2'-AMPS and, probably, 2'-AMP.On the basis of these results and those from previous kinetic and substrate modification studies it is proposed that a second Mg2+ ion might stabilise a conformation in which the adenine moiety of bound 2'-AMP occupies a C-1'-axial ribofuranosyl position through the direct chelation of the second Mg2+ ion to the bridging phosphate ester 2'-O-atom and the ribofuranose ring O-atom.An alternative high-energy arrangement in which the interaction of the second Mg2+ ion with the ribofuranose ring O-atom is mediated via water, such that the conformational strain in the furanose ring is relaxed, but where the entropy of the water is decreased, is also a possibility.
- Cole, Andrew G.,Gani, David
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p. 2685 - 2694
(2007/10/02)
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