Manganese Group Metal Catalyzed Addition Of C(sp~2)-H Bonds To Polar Unsaturated Bonds

In recent years,more and more attention has been paid to achieve functionalization of organic compounds by transition-metal-catalyzed C-H bond activation.Compared with the traditional organic synthetic methods,the direct activation of C-H bonds avoids pre-functionalization of substrates and has lower amount of byproduct and higher atom utilization.In the past few decades,the late transition metal such as palladium,ruthenium,rhodium,iridium catalysts have played an important role in the field of C-H bond activation.Considering the rare reserves,high cost and toxicity remained of these late transition metals,the early transition-metals manganese and rhenium,are gradually put in play by more and more organic chemists,and have made some progress in reactions based on the C-H bond activation.This thesis mainly studies the application of manganese and rhenium catalysts in the field of ortho C-(sp~2)-H bond activation and functionalization.The main contents include the following two parts:(1)We have developed a manganese-catalyzed direct nucleophilic addition reaction of C-(sp~2)-H bond of benzylamines to aldehydes.In this reaction,Mn(CO)5Br was employed as catalyst,FeC l2 as Lewis acid,Me2 Zn as base,and products containing hydroxyl groups were obtained via addition of C-H bond to the carbonyl group of aldehydes.The reaction could achieve high yield conversion regiospecifically with a wide scope o f substrates.Mechanism study demonstrated that dimethyl zinc reacted with the manganese catalyst to produce the methyl manganese active species initially.Methyl anion accepted a proton of benzylamine to release C H4 gas and C-H bond was thus activated.The target product was acquired via insertion of the carbonyl group into Mn-C bond,transmetalation,and hydrolysis.(2)We have developed rhenium-catalyzed C–H bond aminocarbonylation of benzylamines with isocyanates.The reaction could occur effectively with only Re2(CO)10 as catalyst and no bases and additives were required in the reaction.The reaction has good functional group tolerance,and it has good applicability to the substrates containing the electron-withdrawing groups and electron-donating groups.O ne molecule bifunctional substrate could react with the other substrate of two molecule at a time,which provides methodological support for the synthesis of polyamides.