A metal-free N-iodosuccinimde (NIS)/2,2,6,6-tetramethylpiperidinyloxy (TEMPO)-promoted protocol was developed for the oxidative α-cyanation and nitro-Mannich reaction of tertiary amines via a cross-dehydrogenative coupling reaction under mild conditions. Several control experiments were performed; the coupling reaction outcomes indicated that the C-N coupled intermediate (N-Mannich base) formed from the tertiary amine and NIS had a stabilizing effect on the iminium cation.

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NIS/TEMPO‐Promoted Oxidative Cyanation and Nitro‐Mannich Reaction of Tertiary Amines

A metal-free N-iodosuccinimde (NIS)/2,2,6,6-tetramethylpiperidinyloxy (TEMPO)-promoted protocol was developed for the oxidative α-cyanation and nitro-Mannich reaction of tertiary amines via a cross-dehydrogenative coupling reaction under mild conditions. Several control experiments were performed...

Functionalization of furfural can be achieved by photocatalytic C−H activation of the aldehyde and coupling to electron-deficient olefins. With (Bu4N)4W10O32 as the photocatalyst, furfural can be added to benzylidene malononitriles, acrylates, itaconic anhydride, maleic anhydride, 2-vinylpyridine and phenyl vinyl sulfone to form the corresponding furanyl ketones in moderate-to-good yields.

 
<h2>Abstract</h2>
Furfural 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.

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NIS/TEMPO‐Promoted Oxidative Cyanation and Nitro‐Mannich Reaction of Tertiary Amines

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

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