synthesis and catalytic application of 1,1,3,3-tetramethylguanidine modified graphene oxide

graphene oxide (go) was synthesized and functionalized with (3-chloropropyl)-trimethoxysilane (cptms) and then with 1,1,3,3-tetramethylguanidine (tmg) to produce go-si-tmg. the resultant material was characterized by elemental analysis, ft-ir, tga and fe-sem spectroscopy and was used in michael addition of different c-nucleophiles to various substituted nitrostyrenes to explore its catalytic activity. go-si-tmg showed very good catalytic activity and gave a conversion of >99.99% (based on ¹h nmr of the crude reaction mixture) under the optimized reaction conditions (r.t., etoh-h2o (1:1), 1.5 h). moreover, it could be easily recovered through filtration and reused for at least seven times without significant decrease in its catalytic performance.