Synthesis And Studies Of Ru-based Olefin Metathesis Complex And N-aryl Pyrrole Derivatives

Olefin metathesis is a unique carbon skeleton redistribution in which unsaturatedcarbon-carbon bonds are rearranged in the presence of metal carbene complexes. Inrecent years, it has received considerable attention in the field of chemistry, becausethis reaction has the characteristics of mild reaction condition and high yield. In themeantime, with the development of ruthenium catalyst, it had greatly facilitated theapplication of this method in many fields, including polymer chemistry, organicsynthesis, green chemistry, and so on. At present, the research works of Ru-basedcatalysts are still focused on designing and synthetizing of new ligands. Then, peopletry to improve the performance of the ruthenium catalyst according to the electronicand structure property of the ligand. In this paper, we used2,3-Dichloro-1,4-naphthoquinone as the starting material to design and synthesize a new typeruthenium catalyst. The active test shows that this catalyst performs moderately inRCM reactions. This may be due to the NHC is not easy to dissociate from rutheniumcenter, and then the catalyst is hard to produce catalytic activity intermediates whichcan complex with olefins. As a result, the performance of the new catalyst is not asgood as Grubbs second-generation catalyst.Pyrrole derivatives are not only important intermediates in the synthesis ofpharmaceuticals, biologically active natural products, and organic functionalmaterials, but also serve as building blocks in the total synthesis of heterocycliccompounds. Hence, many synthetic strategies have been developed for the synthesisof pyrrole and its derivatives. It includes the Paal-Knorr reaction, Clauson-Kassreaction, transition metal-mediated reaction, reductive coupling, and MW-assistedRCM reaction, RCM tandem oxidative dehydrogenation reaction. We improved theone-pot combination of ring-closing metathesis and in situ oxidative aromatizationdeveloped by Steven’s group. And we developed two efficient catalyst systemsincluding Ru-I/FeCl36H2O and Ru-II/CuCl22H2O which were used in the synthesisof pyrrole derivatives. A series of different substituted N-aryl pyrrole derivatives wereobtained through the two catalytic systems.