Studies On Palladium-catalyzed Selective Transformation Of Aroyl Hydrazides To Construct C-S And C-P Bonds

C-S and C-P bonds are widely exist in natural products,pharmaceutical intermediates,as well as pesticides.As a result,transition metal-catalyzed C-S and C-P bonds formation become an important area in organic synthetic.Being an important sulfur-containing compound,aryl thioether compounds are not only an indispensable part of functional polymer materials,they are also widely exist in various bioactive compounds,containing drug activity and pharmacological activity.Aryl phosphonic compounds are generally applied in catalyses,pesticides,drugs,materials and coordination chemistry,and the efficient synthesis of aryl phosphonic compounds attract chemists.In this thesis,palladium-catalyzed selective transformations of aroyl hydrazides to aryl thioether and aryl phosphonic compundsare include.The contents and the results come as follows:(1)An efficient palladium-catalyzed method for the preparation of thiobenzoate from aroyl hydrazides and disulfide ether has been developed.Using Pd(OAc)2 as a catalyst,all kinds of aroyl hydrazides can produce the corresponding thiobenzoate compounds in high yields.This reaction features good functional groups compatibility,non-poisonous and environmentally friendly.(2)A palladium-catalyzed cross-coupling reaction of C(aryl)-C/P(O)-H bonds to afford aryl phosphonic compunds has been achived.Using Pd(OAc)2 as a catalyst and Na2S2O8 as the oxidant,a variety of aroyl hydrazides could react with hydrogen phosphoryl compounds smoothly.Both electron-donating and electron-withdrawing groups substituent aroyl hydrazides were easily to react with P(O)-H compounds,affording the corresponding product in good yields.In addition,all the three kinds of P(O)-H compounds(eg:H-phosphonates,H-phosphinates and secondary phosphine oxides)could be successfully converted to the corresponding product.Moreover,the chiral phosphorus proceeds in a stereospecific manner with retention of configuration at the phosphorus atom.