The Asymmetric Carbon-Hydrogen Insertion Reaction Of Diazo Compounds With 1,4-Cyclohexadiene Catalyzed By Pincer NCN Iridium Complexes

In this diploma thesis, a series of chiral NCN pincer iridium(III) complexes have been synthesized according to the traditional method of pincer metal complexes in our laboratory. Next, we have explored the catalytic performance of NCN pincer iridium(III) complexes in the asymmetric insertion of 1,4-cyclohexadiene into diazo compounds. The main experimental results are as follows:1. The synthesis of chiral NCN pincer iridium(III) complexesOn the basis of our previous works, we embarked on the reaction of 5-tertiary butyl-m-phthalic acid with SOCl2, affording the acyl chloride. And the chiral amide alcohol was obtained when the acyl chloride was reacted with chiral amino alcohols.Then, chiral bis(imidazolinyl)phenyl ligands 1a-g was constructed after three-step sequence(SOCl2, amine, Na OH, respective)(Scheme 1). In the end, chiral bis(imidazolinyl)phenyl NCN pincer iridium(III) complexes [(Phebim)Ir Cl2(H2O)]2a-g were successfully synthesized through the direct C-H activation of arene in chiral bis(imidazolinyl)phenyl ligands promoted by triply hydrated iridium trichloride.2. The asymmetric C-H insertion reaction of α-diazoarylesters with1,4-cyclohexadiene catalyzed by pincer NCN Iridium complexesThis thesis firstly desribed the reactivity of each chiral pincer NCN Iridium complexes in the C-H insertion reaction of 1,4-cyclohexadiene with methyl phenyldiazoacetate as the modern substrate. After screening the catalysts and reaction temperature, the optimized conditions were obtained, affording a good yield and an excellent enantioselectivity(up to 79% yield and up to 96% ee)(Scheme 2). Under the optimized conditions, a variety of aryldiazoacetates have been examined. Because the corresponding products are the known compounds, the structures only have been characterized by 1HNMR spectrum.3. The asymmetric C-H insertion reaction of 3-diazooxindoles with1,4-cyclohexadiene catalyzed by pincer NCN Iridium complexesWe next explored the catalytic properties of chiral pincer NCN Iridium complexes in the asymmetric C-H insertion reaction of the substrate of3-diazooxindoles with 1,4-cyclohexadiene. After screening the condition of the dosage of catalyst, temperature and solvent etc., this reaction afforded the corresponding product with the yiled of 88% and 93% ee value. Under the optimized conditions, 14 substrates have been extended. All these new compounds have been testsd by 1H NMR, 13 C NMR, 19 F NMR and HRMS spectrum to ensure their structures. The absolute configurations of the catalytic products were confirmed by X-ray diffraction analysis(Scheme 3).