Iron-catalyzed Oxidation And Functionalization Of Sp~3 CH Bond

CDC(Cross Dehydrogenative Coupling)reaction between alcohols and ethers can be applied to generate C-O bond directly and to protect hydroxy which is one of the most significant and synthetically useful methods in organic chemistry.However,Fe catalyzed CDC reaction between alcohols and ethers has not been reported yet.Iron catalyzed oxidation of benzylic sp3 C-H bond to synthesis aldehydes or ketones is a highly useful transformation in organic synthesis.Although some methodologies of iron catalyzed oxidation of benzylic sp3 C-H bond to synthesis aldehydes or ketones have been developed,the selectivity and functional group tolerance are still unmet challenges.Our work mainly includes three parts:(1)the development of iron catalyzed CDC reaction between alcohols and ethers.(2)the development of iron catalyzed oxidation of benzylic sp3 C-H bond to synthesis of aldehydes and ketones.(3)the development of iron catalyzed oxidation of benzylic tertiary C-H bond via C-C bond cleavage to synthesize ketones.The main results of our research are summarized as follows:1.We have developed iron catalyzed CDC reaction between alcohols and ethers.Under the model reaction of cinnamyl alcohol and THF(tetrahydrofuran),reaction conditions were optimized.We obtained the optimum result by using FeBr2 as catalyst,DTBP(Di-t-butyl peroxide)as oxidant,PMHS(polymethyl hydrosiloxane)as additive at 80? under N2 atmosphere.Under the optimized conditions,alcohols and ethers were extended respectively,and most of them resulted in 70-90%yields.A preliminary study of machanism was also conducted.2.We have developed iron catalyzed oxidation of benzylic sp3 C-H bond to synthesis of aldehydes or ketones.The oxidation of toluene was utilized as a model reaction to optimize the reaction conditions.By using Fe(acac)2 as the catalyst,Potassium persulfate(K2S2O8)as the oxidant,MeCN/H2O as the solvent,HSiEt3 as the reductant at 80?,we obtain the optimum result.A series of substrates were investigated under the optimized conditions,mostly target molecules were obtained in 70-90%yields.We also proceeded an initiatory research of the reaction mechanism.3.We have developed iron catalyzed oxidation of benzylic tertiary C-H bond via C-C cleavage.We applied the oxidation of p-bromocumene as the model reaction to optimize the reaction conditions.The optimum result was obtained by utilizing FeCl2 as the catalyst,H2O2 as the oxidant,MeCN/H2O as the solvent at 80?.Additionally,the substrates were explored under optimized conditions.Moreover,a primary study of the reaction mechanism was carried out.