Phenyl α-bromovinyl sulfone in cycloadditions with azomethine ylides: an unexpected facile aromatization of the cycloadducts into pyrroles
作者:Konstantin V. Kudryavtsev、Polina M. Ivantcova、Andrei V. Churakov、Victor A. Vasin
DOI:10.1016/j.tetlet.2012.05.160
日期:2012.8
Phenyl α-bromovinyl sulfone reacts with glycine ester Schiff bases regioselectively in the presence of catalytic amounts of AgOAc and DBU yielding polysubstituted pyrrolidine cycloadducts. Utilization of excess DBU induces subsequent facile aromatization of the cycloadducts and affords 5-arylpyrrole-2-carboxylic acid esters in 39–85% yields in a single step.
Transition Metal-Catalyzed Synthesis of Pyrroles from Dienyl Azides
作者:Huijun Dong、Meihua Shen、Joanne E. Redford、Benjamin J. Stokes、Ashley L. Pumphrey、Tom G. Driver
DOI:10.1021/ol702262f
日期:2007.12.1
A range of 2,5-disubstituted and 2,4,5-trisubstituted pyrroles can be synthesized from dienyl azides at room temperature using catalytic amounts of Znl(2) or Rh-2(O2CC3F7)(4).
Visible-Light Sensitization of Vinyl Azides by Transition-Metal Photocatalysis
作者:Elliot P. Farney、Tehshik P. Yoon
DOI:10.1002/anie.201308820
日期:2014.1.13
Irradiation of vinyl and aryl azides with visible light in the presence of Ru photocatalysts results in the formation of reactive nitrenes, which can undergo a variety of CN bond‐forming reactions. The ability to use low‐energy visible light instead of UV in the photochemical activation of azides avoids competitive photodecomposition processes that have long been a significant limitation on the synthetic
在 Ru 光催化剂存在下用可见光照射乙烯基和芳基叠氮化物会导致反应性氮烯的形成,氮烯可以进行各种 C N 键形成反应。在叠氮化物的光化学活化中使用低能可见光代替紫外线的能力避免了竞争性光分解过程,而竞争性光分解过程长期以来一直是这些反应合成应用的重大限制。