A Base-Promoted Tandem Cycloaddition/Air Oxidation Reaction of Electron-Deficient Conjugated Enynes and Hydrazines: Synthesis of Highly Substituted Pyrazoles
作者:Xiuzhao Yu、Junliang Zhang
DOI:10.1002/chem.201202583
日期:2012.10.8
Rapid access: A base‐mediated cycloaddition/oxidationreaction of hydrazines and electron‐deficient 1,3‐conjugatedenynes gives pyrazole derivatives, some of which are not easily accessible by other methods (see scheme). The reaction conditions are mild, thus enabling a variety of functional groups to be tolerated.
Base-Catalyzed Tandem Michael/Dehydro-Diels-Alder Reaction of α,α-Dicyanoolefins with Electron-Deficient 1,3-Conjugated Enynes: A Facile Entry to Angularly Fused Polycycles
作者:Mingrui Zhang、Junliang Zhang
DOI:10.1002/chem.201302960
日期:2014.1.7
cycloaddition reactions have been the long‐standing hot topic in the synthetic community. Dehydro‐Diels–Alder (DDA) reactions are one class of dehydropericyclic reactions that are derived conceptually by systematic removal of hydrogen atom pairs. A base‐promoted tandem Michael addition and DDA reaction of α,α‐dicyanoolefins with electron‐deficient 1,3‐conjugated enynes was realized in which a DDA reaction takes
DBU-catalyzed tandem additions of electron-deficient 1,3-conjugated enynes with 2-aminomalonates: a facile access to highly substituted 2-pyrrolines
作者:Xiuzhao Yu、Guanghua Zhou、Junliang Zhang
DOI:10.1039/c2cc30840a
日期:——
An efficient, metal free approach to highly substituted 2-pyrrolines by DBU-catalyzed tandem additions (a formal [3+2] cycloaddition) of electron-deficient 1,3-conjugated enynes and 2-aminomalonates under mild conditions was developed.