- 4,6-dimethoxy-1,3,5-triazin-2-yl-d-glycosaminides: Novel substrates for transglycosylation reaction catalyzed by exo-d-glucosaminidase from amycolatopsis orientalis
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A novel sugar adduct, 4,6-dimethoxy-1,3,5-triazin-2-yl-d-glucosaminide (GlcN-DMT), has been prepared by the reaction of d-glucosamine (GlcN) and 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-morpholinium chloride (DMT-MM). The adduct was recognized by exo-d-glucosaminidase (GlcNase) from Amycolatopsis orientalis and transferred the GlcN moiety, giving rise to the corresponding glucosaminides. This chemo-enzymatic process was successfully applied to d-galactosamine (GalN). GalN-DMT prepared directly from GalN and DMT-MM behaved as an efficient glycosyl donor for transfer of the GalN moiety catalyzed by the same enzyme. The introduction of the 4,6-dimethoxy-1,3,5-triazin-2-yl leaving group to the anomeric center significantly enhanced transglycosylating ability, resulting in the efficient glycosidase-catalyzed synthesis of glycosaminides.
- Tanaka, Tomonari,Wada, Tomonori,Noguchi, Masato,Ishihara, Masaki,Kobayashi, Atsushi,Ohnuma, Takayuki,Fukamizo, Tamo,Brzezinski, Ryszard,Shoda, Shin-Ichiro
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- Reaction of Potassium Salts of N-(Thio)phosphorylthioamides with Chlorinated 1,3,5-Triazines
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Potassium salts of N-(thio)phosphorylthioamides can substitute one, two, or three halogen atoms in chlorinated 1,3,5-triazine molecules to give the products of imidothiyl structure. At low temperature, products of incomplete substitution of halogen in the
- Zabirov,Sokolov,Cherkasov
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- Optimized triazine-mediated amidation for efficient and controlled functionalization of hyaluronic acid
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Triazine-based coupling agents have the potential to replace carbodiimides in the functionalization of hyaluronic acid (HA) giving derivatives with high degrees of substitution (DS) under mild conditions with excellent efficiency. Kinetics of the triazine
- Borke, Tina,Winnik, Fran?oise M.,Tenhu, Heikki,Hietala, Sami
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- Cooperation of the Neutral and the Cationic Leaving Group Pathways in Acid-Catalyzed O-Benzylation of TriBOT
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The reaction profile of acid-catalyzed O-benzylation with 2,4,6-tris(benzyloxy)-1,3,5-triazine (TriBOT) was analyzed to study the reaction kinetics. The first-order kinetic constant for the formation of benzyl cation species from N-protonated TriBOT (neutral leaving group pathway) was estimated and compared with that of the model compound for TriBOT. Since rapid consumption of TriBOT in the late stage could not be explained solely by this pathway, cooperation of another reaction mechanism, the cationic leaving group pathway, was proposed to rationalize the rate acceleration.
- Fujita, Hikaru,Hayakawa, Naoko,Kunishima, Munetaka
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- sym-triazine derivatives. 2. Synthesis, properties, and structure of 2-oxo-1,2-dihydro-sym-triazines
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Previously unreported 2-oxo-1,2-dihydro-sym-triazines have been prepared and their alkylation reactions have been studied. It was found that, independently of the structure and nature of the substituent in positions 4 and 6 of the triazine ring or the str
- Mikhailichenko,Chesniyuk,Zavodnik,Firgand,Konyushkin,Zaplishny
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- A Simple Practical Method for the Synthesis of 4,6-Dimethoxy-1,3,5-triazin- 2(1H)-one Using Dimethylamine-Functionalized Solid-Phase Reagents
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A simple practical method for the synthesis of 4,6-dimethoxy-1,3,5-triazin- 2(1H)-one was developed. The desired product was easily obtained from 2-chloro-4,6-dimethoxy-1,3,5-tri-azine and acetic acid by shaking with dimethylamine-functionalized silica ge
- Hioki, Kazuhito,Ohshima, Keiichi,Sota, Yuko,Tanaka, Miki,Kunishima, Munetaka
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- Triazine-Based Cationic Leaving Group: Synergistic Driving Forces for Rapid Formation of Carbocation Species
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A new triazine-based cationic leaving group has been developed for the acid-catalyzed alkylation of O- and C-nucleophiles. There are two synergistic driving forces, namely, stable C=O bond formation and charge-charge repulsive effects, involved in the rapid generation of the carbocation species in the presence of trifluoromethanesulfonic acid (～200 mol %). Considerable rate acceleration of benzylation, allylation, and p-nitrobenzylation was observed as compared to the reactions with less than 100 mol % of the acid catalyst. The triazine-based leaving group showed superior p-nitrobenzylation yield and stability in comparison to common leaving groups, trichloroacetimidate and bromide. A plausible reaction mechanism (the cationic leaving group pathway) was proposed on the basis of mechanistic and kinetic studies, NMR experiments, and calculations.
- Fujita, Hikaru,Kakuyama, Satoshi,Fukuyoshi, Shuichi,Hayakawa, Naoko,Oda, Akifumi,Kunishima, Munetaka
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supporting information
p. 4568 - 4580
(2018/04/26)
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- Privilege Ynone Synthesis via Palladium-Catalyzed Alkynylation of "Super-Active Esters"
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A neat palladium-catalyzed alkynylation reaction was developed with "super-active ester" as the carbonyl electrophile, which provides a clean and efficient synthetic protocol for a broad array of ynone compounds under CO-, Cu-, ligand-, and base-free conditions. The superior activity of triazine ester was rationalized by the strong electron-withdrawing ability and the unique affinity of triazine on palladium. A mechanistic experiment clearly demonstrated that the N-Pd coordination of triazine plays a crucial role for the highly efficient C-O activation. (Chemical Equation presented).
- Yu, Bo,Sun, Huaming,Xie, Zunyuan,Zhang, Guofang,Xu, Li-Wen,Zhang, Weiqiang,Gao, Ziwei
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supporting information
p. 3298 - 3301
(2015/07/15)
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- USE OF A L,3J5-TRIAZIN-2-YL PHOSPHORAMIDATE COMPOUND IN THE SYNTHESIS OF SOFOSBUVIR
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The present invention relates to a new type of 1,3.5-triazin-2-yl phosphoramidates of general formula I with the absolute configuration (S) at the phosphorus atom, an Sp diastereoisomer, wherein R1 and R2 can independently be H, a C1-C6 (un)branched alkyl, a C1-C6 (un)branched alkoxy group, a C1-C6 (un)branched alkylsulfanyl group, C1-C6 (un)branched monoalkylamino or dialkylamino group, including cyclic amino groups, e.g. pyrrolidino, piperidino or morpholino group; and to their use for the production of biologically active phosphoramidate prodrugs, especially sofosbuvir of formula II. Sofosbuvir II is a nucleotide inhibitor of the RNA polymerase, used for the treatment of hepatitis C in the form of a prodrug, releasing the active antiviral agent 2'-deoxy-2'-a-fluoro- P-C-methyluridine-5'-triphosphate in the organism.
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Page/Page column 14
(2015/11/09)
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- Study of the Reactivities of Acid-Catalyzed O-Benzylating Reagents Based on Structural Isomers of 1,3,5-Triazine
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We have demonstrated O-benzylating abilities of both 4,6-bis(benzyloxy)-1,3,5-triazin-2(1H)-one (DiBOT) and 6-(benzyloxy)-1,3,5-triazine-2,4(1H,3H)-dione (MonoBOT), which have been previously suggested as reaction intermediates of the acid-catalyzed benzylation of 2,4,6-tris(benzyloxy)-1,3,5-triazine (TriBOT). We studied the effect on the reactivity of acid-catalyzed O-benzylation caused by the isomeric core triazine structures in these compounds by carrying out a kinetic study and estimating relative basicities using model compounds. Since MonoBOT showed superior reactivity, 1,3,5-triazine-2,4(1H,3H)-dione is a promising core structure for acid-catalyzed alkylating reagents.
- Fujita, Hikaru,Hayakawa, Naoko,Kunishima, Munetaka
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p. 11200 - 11205
(2015/11/18)
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- Bis(4,6-dimethoxy-1,3,5-triazin-2-yl) ether as coupling reagent for peptide synthesis
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Bis(4,6-dimethoxy-1,3,5-triazin-2-yl) ether (4) was prepared by treatment of 2-hydroxy-4,6-dimethoxy-1,3,5-triazine with 2-chloro-4,6-dimethoxy-1,3,5- triazine in 61% yield. Ether 4, isoelectronic with pyrocarbonates, was found capable to activate carboxylic acids in the presence of 1,4-diazabicyclo[2.2.2] octane (DABCO) to yield, under mild reaction conditions, superactive triazine esters. Versatility of this new coupling reagent was confirmed by condensation of lipophilic and sterically hindered carboxylic acids with amines in 71-98% yield, and by synthesis of peptides, including those containing Aib-Aib sequence, in solution with high yield and high enantiomeric purity. Copyright
- Jastrzabek, Konrad,Bednarek, Przemyslaw,Kolesinska, Beata,Kaminski, Zbigniew J.
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p. 952 - 961
(2013/07/28)
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- A dimethoxytriazine type glycosyl donor enables a facile chemo-enzymatic route toward α-linked N-acetylglucosaminyl-galactose disaccharide unit from gastric mucin
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An efficient chemo-enzymatic process for construction of the α-linked disaccharide unit (GlcNAcα1-4Gal) found in gastric mucin has been developed. The process consists of a one-step preparation of a novel triazine type glycosyl donor in water and the subsequent transglycosylation to a galactose derivative catalysed by α-N-acetylglucosaminidase.
- Noguchi, Masato,Nakamura, Miwa,Ohno, Ayaka,Tanaka, Tomonari,Kobayashi, Atsushi,Ishihara, Masaki,Fujita, Masaya,Tsuchida, Akiko,Mizuno, Mamoru,Shoda, Shin-Ichiro
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supporting information; experimental part
p. 5560 - 5562
(2012/07/03)
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- 4,6-Dimethoxy-1,3,5-triazine oligoxyloglucans: Novel one-step preparable substrates for studying action of endo-β-1,4-glucanase III from Trichoderma reesei
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Two kinds of 4,6-dimethoxy-1,3,5-triazine (DMT) oligoxyloglucans, DMT-β-XXXG and DMT-β-XLLG, have been synthesized via one-step procedure starting from the corresponding unprotected oligoxyloglucans in water. The resulting DMT derivatives were found to be hydrolyzed by endo-β-1,4-d-glucanase III from Trichoderma reesei (EGIII) and utilized as substrates for determination of the kinetic parameters of EGIII. The present DMT-method would be a convenient analytical tool for studying the action of glycosyl hydrolases due to the extremely simple synthetic process of DMT-glycosides without using protecting groups.
- Kobayashi, Atsushi,Tanaka, Tomonari,Watanabe, Kazuhito,Ishihara, Masaki,Noguchi, Masato,Okada, Hirofumi,Morikawa, Yasushi,Shoda, Shin-Ichiro
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body text
p. 3588 - 3591
(2010/09/09)
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- Stability of cyanuric acid to photocatalytic degradation
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TiO2, O2, H2O → photocatalytic degradation conditions X = OH, no degradation X= OMe, kH/kD = 3.3 for degradation X= 18OH, no isotope exchange Cyanuric acid is unique among organic molecules in being resistant to photocatalytic degradative conditions by TiO2 in oxygenated water. Trimethyl cyanurate shows an isotope effect of 3.1-3.3 on degradation selectivity when the methyl groups are deuterated, and cyanuric acid enriched in 18O does not exchange hydroxyl groups with bulk water under these conditions. Thus, the tolerance of cyanuric acid to photocatalysis is not due to rapid and reversible addition to the aromatic nucleus.
- Tetzlaff, Troy A.,Jenks, William S.
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p. 463 - 465
(2008/02/11)
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- Stepwise versus concerted mechanisms at trigonal carbon: Transfer of the 1,3,5-triazinyl group between aryl oxide ions in aqueous solution
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Displacements of 4-nitrophenolate ions from 2-(4-nitrophenoxy)-4,6-dimethoxy-1,3,5-triazine by substituted phenolate ions in aqueous solution obey a linear Br?nsted-type equation, log kArO = 0.951pKa - 10.98, over a range of pKa values greater than and less than the pKa of the leaving phenol. The absence of curvature is consistent with a mechanism involving a single transition state. This conclusion is supported by the existence of cross-correlation effects (Pxy = 0.0561) on βnuc of the pKa of the leaving group and on β1g of the pKa of the nucleophile on β1g. The value of βeq, the Br?nsted selectivity for transfer of the triazinyl function between phenolate ions, is calculated from the Br?nsted data to be 1.48. The identity reaction of 3,4-dinitrophenolate ion with the (3,4-dinitrophenoxy)triazine is calculated to have a Kreevoy-Albery τ value of 1.04, indicating that in this case changes in effective charge on entering and leaving ligands are approximately balanced.
- Renfrew, A. Hunter M.,Rettura, Donatella,Taylor, John A.,Whitmore, James M. J.,Williams, Andrew
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p. 5484 - 5491
(2007/10/02)
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- MANGANESE DIOXIDE OXIDATION OF HYDROXYAMINO-sym-TRIAZINES
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The hydroxyamino group in sym-triazines is readily oxidized by the action of manganese dioxide.The stability of the nitrosotriazines formed in this oxidation depends on the electron donor properties of the other substituents in the molecule.
- Sedova. V. F.,Shkurko, O. P.
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p. 593 - 597
(2007/10/02)
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