Practical carbocatalysis by graphene oxide nanosheets in aqueous medium towards the synthesis of diversified dibenzo[1,4]diazepine scaffolds

Abstract

GO nanosheets are found to be an efficient recyclable carbocatalyst for the construction of diversified dibenzo[1,4]diazepine nuclei starting from o-phenylenediamine, various aldehyde/ketone and 1,3-diketo compounds in aqueous medium. This new metal free synthetic protocol also facilitated the formation of coumarine and quinolinone fused novel dibenzo[1,4]diazepines and provided an excellent yield of the corresponding products. In addition, when a substrate contains both the aldehyde and ketone functionality, the reacton offers dibenzo[1,4]diazepines resulting from the chemoselective aldehyde adduct.