342-69-8Relevant articles and documents
Palladium-Catalyzed Thiomethylation via a Three-Component Cross-Coupling Strategy
Wang, Ming,Qiao, Zongjun,Zhao, Jiaoyan,Jiang, Xuefeng
supporting information, p. 6193 - 6197 (2018/09/25)
In this report, the combination of masked inorganic sulfur and dimethyl carbonate was designed to achieve thiomethylated cross coupling of aryl chlorides. Remarkably, this powerful strategy realized thiomethylation of nucleosides bearing unprotected ribose, chloride-containing pharmaceuticals with late-stage coupling, and herbicides possessing multiple heteroatoms and steric hindrance. Moreover, this protocol is practically amenable to multigram-scale synthesis with a lower catalysis loading and a higher yield.
High-throughput five minute microwave accelerated glycosylation approach to the synthesis of nucleoside libraries
Bookser, Brett C.,Raffaele, Nicholas B.
, p. 173 - 179 (2007/10/03)
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.
Nucleic acid related compounds. 86. Nucleophilic functionalization of adenine, adenosine, tubercidin, and formycin derivatives via elaboration of the heterocyclic amino group into a readily displaced 1,2,4-triazol-4-yl substituent
Miles, Robert W.,Samano, Vicente,Robins, Morris J.
, p. 5951 - 5957 (2007/10/02)
Treatment of 9-methyladenine and hydroxyl-protected derivatives of adenosine and 2′-deoxyadenosine with 1,2-bis[(dimethylamino)methylene]hydrazine and/or its dihydrochloride at elevated temperatures in appropriate solvents resulted in elaboration of the 6-amino group into a 6-(1,2,4-triazol-4-yl) substituent in excellent yields. Analogous functionalization of the amino groups of tubercidin {4-amino-7-(β-D-ribofuranosyl)pyrrolo[2,3-d]-pyrimidine} and formycin {7-amino-3-(β-D-ribofuranosyl)pyrazolo[4,3-d]pyrimidine} gave the respective 4- and 7-(1,2,4-triazol-4-yl) derivatives. Nucleophilic replacement of the triazole moiety gave the respective 6-, 4-, and 7-substituted purine, pyrrolo[2,3-d]pyrimidine, and pyrazolo[4,3-d]pyrimidine products. This first general method for "direct" nucleophilic replacement of an amino group on these nitrogen heterocycles also provides a new class of compounds for potential postsynthetic modifications after incorporation into oligonucleotides.