Three-component synthesis of N-sulfonylformamidines in the presence of magnetic cellulose supported N-heterocyclic carbene-copper complex,as an efficient heterogeneous nanocatalyst

A cellulose based magnetic nanocomposite possessing NHC-Cu Complex has been synthesized and characterized. It was then applied as a highly active catalyst in one-pot three-component reaction of sulfonyl azides, secondary amines and triethylamine to afford N-sulfonylformamidines. Copper catalyzed oxidative transformation of C-N bond of triethylamine is a key step to give desired products. In contrast with the good reactivity of the conventional secondary amines, aromatic amines and NH containing heteroaromatics had no activity in these reactions. Moreover, the used nanocatalyst which could be recovered by external magnet, showed reasonable catalytic activity for several times.