Palladium Supported on Mesoporous Silica/Graphene Nanohybrid as a Highly Efficient and Reusable Heterogeneous Catalyst for C-H Functionalization

Mesoporous silica/graphene (KIT-6/G) with pendent 3-mercaptopropyl groups has been prepared by condensation of surface silanols and (3-mercaptopropyl)trimethoxysilane (MPTMS). Treatment of the mercaptopropylated with Pd(CH3CN)2Cl2 gave a heterogeneous Pd-catalyst (Pd@KIT-6/G-SH).[1-3] The catalytic activity of the catalyst was investigated in two types of C-H functionalized for the synthesis of 2-cyanoacetanilide and 2- arylpyridine 1-oxide derivatives via C-H activation. Additionally, for the study of the effect of thiol ligand, the Pd@KIT-6/G was prepared from the treatment of Pd(CH3CN)2Cl2 with KIT-6/G. The catalyst has been successfully recovered and reused without loss of activity over seven cycles of reactions[4], scheme 1.