- Stereoselective Palladium-Catalyzed Arylation of Exo-Glycals with Aryl Iodides
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A novel methodology for the arylation of exo-glycals has been developed. A range of exo-glycals underwent reactions with aryl iodides in the presence of a palladium catalyst. The transformation proceeded in a stereoselective manner to afford Z-isomers. Th
- Regier, Jeffery,Ghanty, Supriya,Bolshan, Yuri
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supporting information
p. 524 - 530
(2022/01/12)
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- Highly (Z)-Diastereoselective Synthesis of Trifluoromethylated exo-Glycals via Photoredox and Copper Catalysis
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Highly (Z)-diastereoselective approaches for the synthesis of trifluoromethylated exo-glycals by copper and photoredox catalysis are described. These complementary reactions are applicable to a wide range of methylene exo-glycals generated from the corresponding pyranoses and furanoses and give trifluoromethylated compounds under mild conditions in moderate to good yields. DFT calculations have allowed a rationalization of the observed (Z)-stereoselectivity.
- Frédéric, Christophe J.-M.,Cornil, Jér?me,Vandamme, Mathilde,Dumitrescu, Lidia,Tikad, Abdellatif,Robiette, Rapha?l,Vincent, Stéphane P.
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supporting information
p. 6769 - 6773
(2018/10/24)
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- Heck-type cross-coupling between halo-exo-glycals and endo-glycals: A practical way to achieve C-glycosidic disaccharides
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An effective Heck-type cross-coupling reaction between halo-exo-glycals and endo-glycals to achieve C-glycosidic disaccharides has been developed. Using Pd(OAc)2 as the catalyst, dppp as ligand and K2CO 3 as base, the reac
- Tao, Yongfeng,Ding, Ning,Ren, Sumei,Li, Yingxia
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p. 6101 - 6104
(2013/10/22)
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- DETECTION OF MYCOBACTERIA
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A method for determining the presence of mycobacteria species in an organism or biological sample, the method comprising adding to the organism or biological sample a probe molecule comprising a substrate and a label, which probe molecule can be incorporated into mycobacteria, the presence of mycobacteria being determined by a detector responsive to the presence of the label, optionally after applying a stimulus; suitable probe molecules include compounds comprising a label and a substrate, which label is can be detected by a detector responsive to the presence of the label, optionally after applying a stimulus, characterised by compound being able to engage with the active site of Antigen 85B (Ag85B) such that it can form simultaneous hydrogen bonds with two or more amino acids in the active site selected from Arg 43, Trp 264, Ser126, His 262 and Leu 42, or the corresponding amino acids in Antigen 85A (Ag85A) or Antigen 85C (Ag85C), at least one of which is with Ser126.
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Page/Page column 38
(2011/04/18)
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- Sonogashira couplings of halo- and epoxy-halo-exo-glycals: Concise entry to carbohydrate-derived enynes
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Furanose- and pyranose-derived mono- and dihalo-exo-glycals undergo Sonogashira coupling reactions in the presence of Pd catalysts to give carbohydrate-derived enynes in a completely stereoselective manner. On the other hand, a furanose-derived 2, 3-anhydrohalo-exo-glycal, available from D-mannose in five steps, undergoes Pd0-catalyzed Sonogashira coupling, leading to 2-deoxyenynes.
- Gomez, Ana M.,Barrio, Aitor,Pedregosa, Ana,Uriel, Clara,Valverde, Serafin,Cristobal Lopez
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body text
p. 2910 - 2920
(2010/08/05)
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- Efficient synthesis of methylene exo-glycals: Another use of glycosylthiomethyl chlorides
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A new approach to the synthesis of methylene exo-glycals is described. Oxidation of glycosylthiolmethyl chloride (GTM-Cl) with mCPBA afforded the corresponding glycosylchloromethyl sulfone in almost quantitative yield, which underwent KOtBu-ind
- Zhu, Xiangming,Jin, Ying,Wickham, John
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p. 2670 - 2673
(2007/10/03)
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- Stereoselective synthesis of substituted exo-glycals from 1-exo-methylene pyranoses
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Halo-exo-glycals of the gluco-, manno- and galacto- series, readily prepared by reaction of 1-exo-methylene pyranoses with iodonium dicollidinium triflate (IDCT), undergo Suzuki or B-alkyl Suzuki cross-coupling reactions with boronic acids or alkyl borane
- Gómez, Ana M.,Pedregosa, Ana,Valverde, Serafín,López, J. Cristóbal
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p. 6111 - 6116
(2007/10/03)
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- Stereochemistry in the synthesis and reaction of exo-glycals.
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Two general methods are explored for the stereoselective synthesis of exo-glycals. One method utilizes a nucleophilic addition of fully protected sugar lactones of gluco-, galacto-, and manno-types, followed by the subsequent dehydration, to give the desired exo-glycals with (Z)-configuration. The other method proceeds with selenylation of C-glycosides in a stereoselective manner. The subsequent selenoxide elimination also provides (Z)-exo-glycals. The prepared exo-glycal conjugated esters of either gluco- or manno-type react with allyl alcohol to give exclusively alpha-anomers.
- Yang, Wen-Bin,Yang, Yu-Ying,Gu, Yu-Feng,Wang, Shwu-Huey,Chang, Che-Chien,Lin, Chun-Hung
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p. 3773 - 3782
(2007/10/03)
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- α(1-3)-galactosyltransferase inhibition based on a new type of disubstrate analogue
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How do retaining glycosyltransferases function? To answer this question, UDP-Gal and galactose were covalently linked to form disubstrate analogues 1, of which surprisingly 1β and not 1α inhibited α(1-3)-galactosyltransferases very well. An understanding
- Waldscheck, Bernhard,Streiff, Markus,Notz, Wolfgang,Kinzy, Willy,Schmidt, Richard R.
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p. 4007 - 4011
(2007/10/03)
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- An efficient synthesis of new 1′-C-methyl-α-O-disaccharides using 1-methylenesugars as the glycosyl donors
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A series of new 1′-C-methyl-α-disaccharides were firstly synthesized by the directly Lewis acid-catalyzed O-glycosidation of 1-methylenesugars used as glycosyl donors. The O-glycosidation afforded stereospecifically the corresponding 1′-methyl-α-O-glycosides whose configurations were tentatively assigned by the NMR spectra, COSY and the C-H coupling constant 3JH-2′,Me-1′. The O-glycosidation of the acetyl protected 1-methylenesugars showed that the acetyl group at the C-2-O position was not effective to control the stereochemistry of the product by neighboring group participation because of the formation of a tertiary oxycarbenium ion as a stable intermediate.
- Li, Xiaoliu,Ohtake, Hiro,Takahashi, Hideyo,Ikegami, Shiro
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p. 4283 - 4295
(2007/10/03)
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