In this presentation, we wish to introduce our explored results for syntehsis of various (arylimido)niobium-alkylidene compelxes, Nb(CHSiMe3)(NAr)(OR)(PMe3)2 [Ar = aryl; R = C(CF3)3, OC6F5 etc.], as catalysts for ring opening metatehsis polymerization of cyclic olefins (norbornene and the derivateves, cyclooctene etc.). These complexes exhbited the remarkable catalytic activites (e.g. TOF 236 sec-1) and effect of ligands toward the activity will be focused.

Recently, amounts of researches focus on lignin depolymerization and the application of its downstream derivatives. Various acid/base catalytic or noncatalytic methods, combined with oxidants or reducing agents, had been explored to depolymerize lignin. In the present studies, we explored the effects of different ionic liquids (ILs) on various lignin depolymerization in ethylene glycol (EG) using a continuous flow fixed-bed reactor. A high aromatics yield was obtained under low basicity environment. Besides, we also analyzed the factors influencing the condensation process of diverse fragments from lignin degradation and brought forward the possible lignin conversion mechanism.

Nitrogen-doped carbon-supported cobalt was employed as a non-noble metal catalyst to study the reaction kinetics of concentrated aqueous solutions of acetal-protected 5-hydroxymethylfurfural to furan-2,5-dicarboxylic acid in high yield, using pressurized air as oxidant.