Weak Coordination Group Assisted Regioselective Carbon-carbon Bonding Reactions

Carbon-carbon bonds are the basis of organic compounds,which exists widely in organic molecules.Although the construction of carbon-carbon bonds has been widely reported.However,the C-H functionalizations catalyzed by transition metals such as Ru,Rh,and Pd have become hotspots in recent years due to their unique advantages.This thesis mainly studies the direct alkenylation and arylation of C-H bonds catalyzed by transition metals,and realizes the weak hydrogenation center induced alkenylation and arylation of hydrocarbon bonds.The main contents are as followsIn the first part,a summary of the C-H functionalizations that have been reported is described,mainly including the transition metal-catalyzed alkenylation and arylation reactions.And two different alkenylation products can be obtained by regulating the temperature,which has good application valueIn the second part,a new strategy for constructing C-C bond by Rh(?)catalyzing the ortho alkenylation of phenolic compounds induced by acetoxime ethers as weak coordination centers.This new method has several superiorities of moderate reaction conditions,high to excellent yields,high regioselectivity,broad substrate scope and good functional group tolerance.Moreover,two different alkenylation products can be obtained by regulating the temperature,which has good application valueIn the third part,the direct arylation of 3-butenoic acid catalyzed by Pd(?).In this transform,an available commercial reagent 3-butenoic acid and a highly effective arylization reagent arylsulfonyl hydrazide have been used as substrates Under mild conditions,the 4-phenyl-3-butenoic acid which is used as drug molecular is obtained in one step.This strategy does not require a supernumerary guiding group.thus avoiding the complex operation and product loss of cutting the guiding group.This new method has several superiorities of moderate reaction conditions,high to excellent yields,easy operation,and strong substrate adaptability,It has good application prospects.