title: 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.
abstract: Angularly fused carbocyclic frameworks and their heteroatom-substituted analogues exist in many natural products that display a broad and interesting range of biological activities. Preparation of polycyclic products by 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 place between the arylalkynes and electron-deficient tetrasubstituted olefin. The control experiments support the stepwise anionic reaction pathway rather than the concerted reaction pathway.
authors.affiliation: Shanghai Key Laboratory of Green Chemistry and Chemical Processes. Department of Chemistry, East China Normal University, Shanghai 200062 (P. R. China).
authors.forename: Mingrui
authors.initials: M
authors.lastname: Zhang
authors.forename: Junliang
authors.initials: J
authors.lastname: Zhang
keywords: Diels-Alder reactions; Michael reactions; domino reactions; enynes; polycycles