Decatungstate‐Catalyzed Carbon‐Carbon Bond Formation Between Furfural and Electron‐Deficient Olefins

Abstract

AbstractFurfural is produced on a large commercial scale from lignocellulose and can be used for the preparation of several industrial chemicals with four to five carbon atoms. Further functionalization of furfural by C−H activation, however, is less widely developed. In the present work, tetrabutylammonium decatungstate is investigated as an inexpensive photocatalyst for activating the aldehyde C−H bond and mediate a coupling between furfural and electron‐deficient olefins. The results show that furfural can be successfully added to benzylidene malononitriles, acrylates, itaconic anhydride, maleic anhydride, 2‐vinylpyridine and phenyl vinyl sulfone to generate the corresponding furanyl ketones in moderate‐to‐good yields. The electronic properties of the electron‐deficient olefins are instrumental for achieving a favorable reaction with furfural. The findings show how photocatalysis can be used to form new carbon‐carbon bonds from a platform molecule, which in this way can be converted into a number of more advanced structures.