- 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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- Deaza analogues of adenosine as inhibitors of blood platelet aggregation
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A number of deaza analogues of adenosine were prepared and tested as inhibitors of platelet aggregation induced by ADP and collagen to investigate the structure-activity relationships in this class of nucleoside analogues. The results showed that the presence of a 6-amino group and nitrogen atoms at positions 3 and 7 of the purine moiety are required for inhibitory activity.
- Antonini,Cristalli,Franchetti,Grifantini,Martelli,Petrelli
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p. 366 - 369
(2007/10/02)
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- Synthesis of N-Glycosides of 1H-Imidazopyridine
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3-β-D-Ribofuranosyl-3H-imidazopyridine (7), 3-β-D-xylofuranosyl-3H-imidazopyridine (9) and 3-α-L-rhamnopyranosyl-3H-imidazopyridine (11) have been synthesised.Condensation of silylated derivative (2) of 1H-imidazopyridine (1) s
- Gupta, P. K.,Bhakuni, D. S.
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p. 817 - 819
(2007/10/02)
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