Pyridinium ylide-assisted KY zeolite catalyzed tandem synthesis of polysubstituted cyclopropanes

Abstract

Abstract A new method is reported for the synthesis of polysubstituted cyclopropanes from substituted benzyl halides, aromatic aldehydes and acetonitrile derivatives catalyzed by KY zeolite in acetonitrile for 20 h at room temperature. Cycloaddition of the intermediate pyridinium ylide to electron-deficient olefins (in situ) affords diastereomerically pure polysubstituted cyclopropanes in high yields (up to 96%). This one-pot two-step tandem reaction results in the synthesis of substituted cyclopropane containing building blocks, which are important intermediates in the synthesis of natural products. This multicomponent reaction also realizes the use of KY zeolite as a green, heterogeneous and environmentally benign solid base catalyst, which is recovered and reused without loss in its activity.