A Novel Chemo-, Regio, And Stereoselective Dioxygenation Of Aryl Olefins

A novel, economical and environmentally friendly synthesis of aryl glycol monoesters from aryl olefins using hydrogen peroxide as the final oxidant catalyzed by ruthenium chloride has been reported in this dissertation.The heuristic and optimizing process of this new aryl olefin selective oxidation system has been reported in the first part of this dissertation. We performed a set of preliminary experiments on stilbene as a model substrate using 30% hydrogen peroxide in the presence of various catalysts and solvents at room temperature. Finally, an efficient dioxygenation system of aryl olefins with 0.02 eq ruthenium chloride as catalyst and using 2 eq 30% hydrogen peroxide as oxidant was established.The applicability of this new catalytic oxidation system has been examined in the second part of this dissertation. Various aryl olefins were converted into the corresponding aryl glycol monoesters with in 15-40 min at room temperature, while this catalytic oxidation system has no effect on alkyl olefins. Indole derivatives were dioxygenated slowly under the oxidation of peracetic acid which was formed from acetic acid and hydrogen peroxide, and gave trans dioxygenation products.The chemoselective dioxygenation of aryl carbon-carbon double bonds of this new catalytic oxidation system has been investigated in the third part of this dissertation. Experiments of intramolecular competition showed that the procedure could be successfully used in the selective dioxygenation of aryl carbon-carbon double bonds with no influence on alkyl carbon-carbon double bonds.Another outstanding characteristic has been examined in the forth part of this dissertation. We select several substrates and test the TON and TOF of their oxidation under this system. Moreover, a plausible concerted [5+2] cycloaddition mechanism for the selective dioxygenation of aryl olefins is proposed.In conclusion, the first chemo-, regio-, and stereoselectivity dioxygenation of aryl olefins reported herein are operationally simple, and with superior economical and environmentally friendly characteristics. It represents new routs for the synthesis of some chemical and pharmaceutical products.