Synthesis of a series of five-membered sultams containing different hetero- or carbocycles were obtained in good to excellent yields by ring-closing metathesis (RCM) reaction. Many sultams were precipitated from the reaction mixture and they were easily separated by filtration without further purification.
An expedient approach for the synthesis of pyrrolo[3,2-d]pyrimidines (9-deazaxanthines) and furo[3,2-d]pyrimidine via radical cyclization
作者:K.C. Majumdar、Shovan Mondal
DOI:10.1016/j.tet.2009.09.059
日期:2009.11
A new efficient route for the synthesis of substituted 9-deazaxanthines in excellent yields via aza-Claisen rearrangement followed by radical cyclization has been achieved. This methodology has also been applied to the synthesis of furo[3,2-d]pyrimidine.
通过氮杂-克莱森重排,然后进行自由基环化,已经获得了一种新的有效途径,用于以优异的产率合成取代的9-脱氮黄嘌呤。该方法也已经应用于呋喃并[3,2- d ]嘧啶的合成。
Concise Synthesis of Pyrimido-azocine Derivatives via Aza-Claisen Rearrangement and Intramolecular Heck Reaction
An expedient approach involving BF3˙OEt2-catalyzed aza-Claisen rearrangement and palladium-catalyzed intramolecular Heck reaction for the synthesis of pyrimidine-fused azocine derivatives is described. The mechanistic interpretation of the plausible mode of cyclization is also described. uracil - aza-Claisen rearrangement - azocine - Heck reaction
Concise Access to Pyrimidine-Annulated Azepine and Azocine Derivatives by Ruthenium-Catalyzed Ring-Closing Metathesis
作者:K. Majumdar、Shovan Mondal、Debankan Ghosh
DOI:10.1055/s-0029-1219228
日期:2010.4
systems are commonly undertaken throughcyclization and cycloaddition reactions, but the formation of seven- and eight-membered-ring systems are not as abundant. An efficient and high-yielding method for the synthesis of seven- and eight-membered-ring nitrogen-containing heterocycles by ring-closingmetathesis is reported. uracil - azepine - azocine - ring-closingmetathesis
Synthesis of a series of five-membered sultams containing different hetero- or carbocycles were obtained in good to excellent yields by ring-closing metathesis (RCM) reaction. Many sultams were precipitated from the reaction mixture and they were easily separated by filtration without further purification.
An expedient approach for the regioselective synthesis of novel 1,5,6,7-tetrahydro-2H-pyrrolo[3,2-d]pyrimidine-2,4(3H,5H)-dione derivatives via Fe (III)-mediated iodocyclization
作者:Subhadeep Samanta、Shovan Mondal
DOI:10.1016/j.tetlet.2022.154223
日期:2022.12
Novel pyrrolo[3,2-d]pyrimidine derivatives have been synthesized by an efficient and regioselective Fe (III)-mediated iodocyclization method starting from a commercially available uracil compound. Here, iron has a dual role in the iodocyclization process by acting as a Lewis acid which promotes the release of I+ cation from iodine by removing iodide ion, and also as an oxidant which again generates
新型吡咯并 [3,2- d ] 嘧啶衍生物已通过有效且区域选择性的 Fe (III) 介导的碘环化方法从市售尿嘧啶化合物开始合成。在此,铁在碘环化过程中具有双重作用,既作为路易斯酸通过去除碘离子促进碘释放 I +阳离子,又作为氧化剂从碘离子再次生成碘参与催化反应循环。