- Method for preparing N6-benzoyladenosine
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The invention discloses a method for preparing N6-benzoyladenosine. The method comprises the following steps: (1) weighing and adding adenosine and a protectant in a flask, adding a solvent and a catalyst, carrying out stirring refluxing for a period of t
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Paragraph 0026-0028; 0031-0033; 0036-0038; 0041-0043; 0046
(2021/02/10)
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- A solid-supported acidic oxazolium perchlorate as an easy-handling catalyst for the synthesis of modified pyrimidine nucleosides via Vorbrüggen-type N-glycosylation
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A solid-supported acidic oxazolium perchlorate was investigated as a heterogeneous catalyst in N-glycosylation reactions using silylated modified pyrimidines and an acylated ribose or glucose to afford the corresponding pyrimidine nucleosides. This salt is a nonhygroscopic and stable powder whose activity is comparable to that of 2-methyl-5-phenylbenzoxazolium perchlorate. A reaction with this polymer catalyst can be conducted on a gram scale. Reusability of the solid-supported catalyst was also investigated.
- Basu, Nabamita,Oyama, Kin-ichi,Tsukamoto, Masaki
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supporting information
p. 1921 - 1924
(2017/04/27)
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- High-throughput five minute microwave accelerated glycosylation approach to the synthesis of nucleoside libraries
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The Vorbrueggen glycosylation reaction was adapted into a one-step 5 min/130 °C microwave assisted reaction. Triethanolamine in acetontrile containing 2% water was determined to be optimal for the neutralization of trimethylsilyl inflate allowing for direct MPLC purification of the reaction mixture. When coupled with a NH3/methanol deprotection reaction, a high-throughput method of nucleoside library synthesis was enabled. The method was demonstrated by examining the ribosylation of 48 nitrogen containing heteroaromatic bases that included 25 purines, four pyrazolopyrimidines, two 8-azapurines, one 2-azapurine, two imidazopyridines, two benzimidazoles, three imidazoles, three 1,2,4-triazoles, two pyrimidines, two 3-deazapyrimidines, one quinazolinedione, and one alloxazine. Of these, 32 yielded single regioisomer products, and six resulted in separable mixtures. Seven examples provided inseparable regioisomer mixtures of -two to three compounds (16 nucleosides), and three examples failed to yield isolable products. For the 45 single isomers isolated, the average two-step overall yield ± SD was 26 ± 16%, and the average purity ± SD was 95 ± 6%. A total of 58 different nucleosides were prepared of which 15 had not previously been accessed directly from glycosylation/deprotection of a readily available base.
- Bookser, Brett C.,Raffaele, Nicholas B.
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p. 173 - 179
(2007/10/03)
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- Benzoyl cyanide: A mild and efficient reagent for benzoylation of nucleosides
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Efficient benzoylation of various nucleosides has been accomplished in pyridine with a catalytic amount of DMAP and benzoyl cyanide under mild conditions.
- Prasad, Ashok K.,Kumar, Vineet,Maity, Jyotirmoy,Wang, Zhiwei,Ravikumar, Vasulinga T.,Sanghvi, Yogesh S.,Parmar, Virinder S.
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p. 935 - 945
(2007/10/03)
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- Mild, efficient, selective and "green" benzoylation of nucleosides using benzoyl cyanide in ionic liquid
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Use of benzoyl cyanide (BzCN) for benzoylation of nucleosides has been studied, both in pyridine and in ionic liquid. BzCN in 1-methoxyethyl-3- methylimidazolium methanesulfonate as ionic liquid has been found to be a "green" alternative compared to the pyridine-BzCN system. An efficient and selective benzoylation of nucleosides of both, the 2′-deoxy- and the ribo-series at ambient temperature was accomplished. Copyright Taylor & Francis, Inc.
- Prasad, Ashok K.,Kumar, Vineet,Maity, Jyotirmoy,Sanghvi, Yogesh S.,Ravikumar, Vasulinga T.,Parmar, Virinder S.
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p. 747 - 751
(2007/10/03)
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- The synthesis of [(β-D-ribofuranosyloxy)-methyl]nucleosides
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The coupling reaction of acetoxymethoxy ribofuranoside 4 with nucleic acid bases 5a-f to synthesize novel (ribofuranosyloxy)methyl uracil, thymine, cytosine, adenine, guanine derivatives 6a-g respectively in preference to the expected formation of natural nucleosides 2′,3′,5′ -tri-O-benzoyl uridine, methyluridine, cytidine, adenosine and guanosine 7a-g is described. Detailed study of these reactions catalysed by Lewis acids TMSOTf and SnCl4 is described. TMSOTf exhibited selectivity for the formation of ribofuranosyloxy methyl derivatives 6a-g rather than 7a-g. Reason for formation of 6a-g is explained by HSAB principle.
- Mereyala, Hari Babu,Mamidyala, Sreeman Kumar
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p. 655 - 669
(2007/10/03)
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- Effective anomerisation of 2′-deoxyadenosine derivatives during disaccharide nucleoside synthesis
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The formation of a disaccharide nucleoside (11) by O3′-glycosylation of 5′-O-protected 2′-deoxyadenosine or its N6-benzoylated derivative has been observed to be accompanied by anomerisation to the corresponding α-anomeric product (12). The latter reaction can be explained by instability of the N-glycosidic bond of purine 2′- deoxynucleosides in the presence of Lewis acids. An independent study on the anomerisation of partly blocked 2′-deoxyadenosine has been carried out. Additionally, transglycosylation has been utilized in the synthesis of 3′-O-β-D-ribofuranosyl-2′-deoxyadenosines and its α-anomer.
- Gulyaeva, Irma V.,Neuvonen, Kari,Loennberg, Harri,Rodionov, Andrei A.,Shcheveleva, Elena V.,Bobkov, Georgii V.,Efimtseva, Ekaterina V.,Mikhailov, Sergey N.
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p. 1849 - 1864
(2007/10/03)
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- Synthesis of n6,2′,3′,5′-tetrabenzoyl-β-d-adenosine catalyzed by metal iodides
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N-Glycosylation of N6-benzoyl-N6,N9-bis(trimethylsilyl)adenine with methyl 2,3,5-tri-O-benzoyl-β-D-ribofuranosyl carbonate was effectively promoted by several metal iodides and a desired coupling product, N6, 2′
- Nagai, Masashi,Matsutani, Takafumi,Mukaiyama, Teruaki
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- An efficient method for the synthesis of β-D-ribonucleosides catalyzed by metal iodides
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Several β-D-ribonucleosides were synthesized in high yields under mild conditions by N-glycosylations of methyl 2,3,5-tri-O-benzoyl-β-D-ribofuranosyl carbonate (1) with trimethylsilylated nucleoside bases in acetonitrile using a catalytic amount of metal iodide such as SnI2, SbI3 or TeI4. A deprotection of N6-benzoyl group of coupling product took place to a considerable extent when N6-benzoyl-N6,N9-bis(trimethylsilyl)adenine was employed as a nucleoside base using SnI2 or SnCI2 as a catalyst while it was minimized when SbI3 or TeI4 was used. Further, the N-glycosylation of 1 with 7-trimethylsilyltheophylline in the presence of a catalytic amount of metal iodide was more effectively achieved in nitrile solvents other than acetonitrile.
- Mukaiyama, Teruaki,Nagai, Masashi,Matsutani, Takafumi,Shimomura, Naoyuki
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- Stereoselective syntheses of β-D-ribonucleosides catalyzed by the combined use of silver salts and diphenyltin sulfide or Lawesson's reagent
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β-D-Ribonucleosides are stereoselectively synthesized in high yields from methyl 2,3,5-tri-O-benzoyl-β-D-ribofuranosyl carbonate and trimethylsilylated nucleoside bases by the use of [diphenyltin sulfide/silver salt] or [Lawesson's reagent/silver salt] combined catalyst system under mild conditions.
- Shimomura,Matsutani,Mukaiyama
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p. 3100 - 3106
(2007/10/02)
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- Tin(II) Chloride Catalyzed Synthesis of β-D-Ribonucleosides
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Several β-D-ribonucleosides are stereoselectively synthesized in high yields from methyl 2,3,5-tri-O-benzoyl-β-D-ribofuranosyl carbonate and trimethylsilylated nucleoside bases such as pertrimethylsilylated uracil and adenine under mild conditions by using a catalytic amount of tin(II) chloride, a weak Lewis acid.
- Mukaiyama, Teruaki,Matsutani, Takafumi,Shimomura, Naoyuki
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p. 2089 - 2092
(2007/10/02)
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- Pentenyl Ribosides: New Reagents for Purine Nucleoside Synthesis
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Protected pent-4-enyl ribosides and deoxyribosides were synthesized as reagents for the preparation of nucleosides and deoxynucleosides.Reaction of pent-4-enyl 2',3',5'-tri-O-benzoyl-D-erythro-pentofuranoside with five nucleobases in the presence of N-iod
- Chapeau, Marie-Christine,Marnett, Lawrence J.
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p. 7258 - 7262
(2007/10/02)
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- Catalytic Stereoselective Synthesis of β-Ribonucleosides from Methyl Ribofuranosyl Carbonate and Trimethylsilylated Nucleoside Bases by Combined Use of Silver Salts and Diphenyltin Sulfide
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Catalytic stereoselective synthesis of several ribonucleosides from 2,3,5-tri-O-benzoyl-β-D-ribofuranosyl methyl carbonate and trimethylsilylated nucleoside bases is efficiently carried out by combined use of silver salts and diphenyltin sulfide (Ph2Sn=S) under mild conditions.
- Mukaiyama, Teruaki,Matsutani, Takafumi,Shimomura, Naoyuki
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p. 1627 - 1630
(2007/10/02)
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- Condensation of 1-Fluorofuranones and Silylated Nucleobases Catalyzed by Tetrafluorosilane
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The title reaction provides a generally useful tool for nucleoside synthesis.The stereoselectivities are highly influenced by the fluoride substrates, and steric course of the reaction of O-benzylated ribofuranosyl fluoride is solvent dependent.
- Noyori, Ryoji,Hayashi, Masahiko
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- REGIOSELECTIVE PROTECTION OF CARBOHYDRATE DERIVATIVES. PART. 20. SIMPLE, EFFICIENT 2'-O-DEACYLATION OF FULLY ACYLATED PURINE AND PYRIMIDINE RIBONUCLEOSIDES THROUGH tert-BUTOXIDE
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A simple treatment of fully aroylated purine and pyrimidine ribonucleosides with pulverized potassium tert-butoxide in tetrahydrofuran (THF) or dichloromethane under a controlled condition gave a mixture of the corresponding di-O-aroyl derivatives in which 2'-OH derivatives are preponderant over 3'-OH derivatives; 3',5'-di-O-benzoyluridine, N4,3',5'-tribenzoylcytidine, N4,3',5'-tri-O-toluoylcytidine, N2,3',5'-tribenzoylguanosine, and N2,isobutyryl-3',5'-di-O-benzoylguanosine were obtained crystalline in 80 percent, 78 percent, 72 percent, 67 percent, and 65 percent yields, respectively.
- Nishino, Shigeyoshi,Takamura, Hatsuko,Ishido, Yoshiharu
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p. 1995 - 2004
(2007/10/02)
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- Nucleoside Syntheses, XXV. A New Simplified Nucleoside Synthesis
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The several steps of the Friedel-Crafts catalyzed silyl-Hilbert-Johnson nucleoside synthesis - silylation of the heterocyclic base, silylation of the perfluorosulfonic acids or its salts (if SnCl4 is not used as catalyst) and finally the nucleoside synthesis itself - can be combined to a simple one-step/one-pot reaction which generally affords nucleosides in high yields.
- Vorbrueggen, Helmut,Bennua, Baerbel
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p. 1279 - 1286
(2007/10/02)
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