Tetrasubstituted Furans by a PdII-Catalyzed Three-Component Michael Addition/Cyclization/Cross-Coupling Reaction

摘要

The design and discovery of new reactions for the synthesis of highly substituted furans has been stimulated by their appearance in many bioactive natural products and important pharmaceuticals.[1], [2] There has been recent focus on the development of metal-catalyzed one- or two-component reactions for synthesis of these types of compounds, including the cyclization of allenyl ketones,[3] 3-alkyn-1-ones,[3k], [4] 1-(1-alkynyl)-cyclopropyl ketones,[5] (Z)-2-en-4-yn-1-ols,[6] and 2-(1-alkynyl)-2-alken-1-ones,[7] and cycloisomerization of cyclopropyl ketones[8]/cyclopropenyl ketones.[9] Recently, the design of multicomponent reactions[10] that preserve atom economy in a one-pot reaction has attracted attention becasue of the application to efficient construction of molecular structures. Herein we report results of a PdII-catalyzed three-component Michael addition/cycliztion/cross-coupling reaction to afford highly functionalized tetrasubstituted furans.