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
An easy access to pyrimidine-fused azocine derivatives by thiophenol-mediated radical cyclization via 8-endo-trig mode
作者:K.C. Majumdar、Shovan Mondal、Debankan Ghosh
DOI:10.1016/j.tetlet.2009.11.020
日期:2010.1
An efficient route for the synthesis of eight-membered nitrogen heterocycles has been developed via a thiophenol-mediated intramolecular 8-endo-trig radical cyclization. The radical precursors were prepared using BF3·Et2O-catalyzed aza-Claisenrearrangement followed by the reaction with propargyl bromide. The alkenyl radicals are generated from thiophenol initiated by the benzoyl peroxide instead of
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 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