Siddiqui Ibadur R, Siddiqui Naz Akhtar, Shamim Shayna, Srivastava Anjali
Laboratory of Green Synthesis, Department of Chemistry, University of Allahabad, Allahabad, Uttar Pradesh, India.
Nucleosides Nucleotides Nucleic Acids. 2013;32(8):453-63. doi: 10.1080/15257770.2013.809456.
An efficient one-pot three-component synthesis of thiadiazole N-nucleosides with high atom economy from β-D-ribosylhydrazine, aryl thiamide, and aromatic aldehyde promoted by (diacetoxyiodo)benzene under microwave irradiation is reported. The strategy involves formation of thiourea derivatives by microwave-assisted addition of an arylisothiocyanate formed in situ by (diacetoxyiodo)benzene-promoted oxidative rearrangement of an aryl thiamide with Schiff bases of β-D-ribosylhydrazine and a substituted/unsubstituted aromatic aldehyde. The thiourea intermediate on intramolecular heterocyclization yielded thiadiazole N-nucleosides, 2-(arylimino)-3-(β-D-ribosyl)-5-aryl-1,3,4-thiadiazoles. The whole reaction sequence proceeded with quantitative transformation of reactants into thiadiazole N-nucleosides at an ambient temperature. The reaction sequence is supported by isolation of Schiff bases and their quantitative conversion into final product by reaction with arylisothiocyanate under the same reaction conditions.
报道了在微波辐射下，由（二乙酰氧基碘）苯促进，以β-D-核糖酰肼、芳基硫酰胺和芳香醛为原料，通过高效的一锅三组分合成法，以高原子经济性合成噻二唑N-核苷。该策略包括通过微波辅助加成原位生成的芳基异硫氰酸酯来形成硫脲衍生物，该芳基异硫氰酸酯是由（二乙酰氧基碘）苯促进芳基硫酰胺与β-D-核糖酰肼的席夫碱和取代/未取代的芳香醛发生氧化重排反应生成的。硫脲中间体通过分子内杂环化反应生成噻二唑N-核苷，即2-（芳基亚氨基）-3-（β-D-核糖基）-5-芳基-1,3,4-噻二唑。整个反应序列在室温下以反应物定量转化为噻二唑N-核苷的方式进行。该反应序列得到了席夫碱的分离以及在相同反应条件下与芳基异硫氰酸酯反应将其定量转化为最终产物的支持。
