Synthesis And Application Of N-Heterocyclic Carbene Metal Complexes Based On1,1’-Binapthyl Scaffold, And Gold-catalyzed Cyclization Oxidative Coupling Of Allenoates And Organobronic Acids

This thesis was mainly focused on the synthesis of N-heterocyclic carbene (NHC) palladium(Ⅱ), platinum(Ⅱ), and gold(Ⅰ) complexes derived from1,1’-binaphthalenyl-2,2’-diamine (BINAM) or H8-BINAM, and applications of these complexes in the catalytic transformations. Also, gold-catalyzed cyclization oxidative coupling of allenoates and organobronic acids had been discussed. It was divided into five parts.1(NHC)-Pd(II) complexes catalyzed asymmetric1,2-additionChiral C2-symmetric N-heterocyclic carbene (NHC) palladium complexes Ⅰ-6a-c,Ⅰ-7and Ⅰ-14have been prepared from (R)-1,1’-binaphthalenyl-2,2’-diamine (BINAM) or (R)-H8-BINAM and fully characterized by NMR, MS and IR spectroscopies. The structure of complex Ⅰ-14was also confirmed by its X-ray single-crystal diffraction study. NHC-Pd(II) complex Ⅰ-6a was found to be a fairly effective catalyst in asymmetric1,2-addition of arylaldehydes with arylboronic acids to give the corresponding adducts in up to over99%yields and65%ee. It also provided an effective synthetic route for the preparation of biologically active chiral diaryl alcohols compounds. In this catalytic asymmetric reaction, aryl aldehydes and aryl boronic acids have very subtle electronic and steric effects on the reaction outcome. Efforts are underway to elucidate the mechanistic details of this asymmetric addition reaction in the presence of chiral NHC-Pd(II) catalyst and to disclose the exact structure of the active species in this catalytic system.2(NHC)-Pd(II) complexes catalyzed asymmetric fluorinationChiral C2-symmetric (NHC)-Pd(II) complexes Ⅱ-2,Ⅱ-3, and Ⅰ-14have been prepared from (S)-1,1’-binaphthalenyl-2,2’-diamine (BINAM) or (R)-H8-BINAM and fully characterized by NMR, MS and IR spectroscopies.(NHC)-Pd(Ⅱ) complex II-2b was found to be a fairly effective catalyst in asymmetric fluorination of oxindoles to give the corresponding products in up to99%yields and59%ee. In this catalytic asymmetric reaction, steric effects and electronic properties of substrate affected the asymmetric induction. Changing the N-Boc-protecting group greatly affected the asymmetric outcome, respectively, suggesting that the N-Boc-protecting group played a significant role in this reaction. The N-Boc-protecting group of oxidoles avoid steric repulsion with the N-Bn group of catalyst Ⅱ-2b by analysing the transition state for the enantioselectivity, but the free rotating N-Bn group will reduce the enantioselectives.3(NHC)-Platinum(Ⅱ) complex as pre-catalyst for the intramolecular hydroamination and oxidative amination of o-alkenic amines(NHC)-Pt(Ⅱ) complex Ⅲ-2have been prepared from BINAM, subsquently the (NHC)-Pt(Ⅱ) complex Ⅲ-7obtained by reacting with AgBF4to change the ligands. They fully characterized by NMR, MS and IR spectroscopies. The structure of complex III-2and Ⅲ-7were also confirmed by its single-crystal X-ray diffraction study. The (NHC)-Pt(Ⅱ) complex Ⅲ-2/AgBF4was found to be a highly effective catalytic system for the intramolecular hydroamination of olefins affording the corresponding products in excellent yields. The1,2-disubstituted alkene also underwent hydroamination under the same conditions. Whether the N-protecting group was an electron-donating or-withdrawing group, the reactions proceeded smoothly to give the corresponding products in excellent yields. Unfortunately, hydroamination product III-4a was obtained in98%yield and3%ee in the presence of chiral NHC-Pt(Ⅱ)-complex Ⅲ-2and AgBF4. The NHC-Pt(Ⅱ) complex Ⅲ-2/AgBF4also was found to be a highly effective catalytic system for the oxidative amination of co-alkenic amines, affording the indole derivatives in moderate yields. NHC-Pt(II) complex Ⅲ-7has the similar catalytic capability as that of NHC-Pt(Ⅱ) complex Ⅲ-2/AgBF4, and only the NHC-Pt(II) complex Ⅲ-2could not catalyze the intramolecular hydroamination, so the NHC-Pt(Ⅱ) complex Ⅲ-7should be considered as a catalytic activity intermedium. A plausible reaction mechanism has been proposed on the basis of previous literature.4(NHC)-Binuclear-gold complexes catalyzed aminoarylation of olefins(NHC)-binuclear gold complexes and mononuclear gold complex have been successfully prepared from1,1’-binaphthalenyl-2,2’-diamine (BINAM) in good yields. Their structures have been unambiguously determined by spectroscopic data and X-ray diffraction. On the basis of X-ray diffraction, a weak interaction between Au-Au has been identified in the (NHC)-binuclear gold complex IV-4b, in which the distance of Au(Ⅰ)-Au(Ⅰ) is4.190A. We also found that (NHC)-binuclear gold complex IV-4b is a more effective catalyst than that of (NHC)-mononuclear gold complex IV-6in the aminoarylation of olefins under identical conditions. Based on these experimental data, the improved yield of aminoarylation is possibly attributed to the weak Au(Ⅰ)-Au(Ⅰ) interaction in the (NHC)-binuclear gold complex IV-4b. A plausible reaction mechanism has been proposed on the basis of previous literature. Interestingly, the2-(fluoromethyl)-2-methyl-4,4-diphenyl-l-tosylpyrrolidine was obtained by intramolecular hydroamination/fluoration when1,1-disubstituted alkene is starting material.5Gold-catalyzed cyclization oxidative coupling of allenoates and organobronic acidsThe PPh3AUCl was found to be a highly effective catalyst for cyclization oxidative coupling of allenoates and organobronic acids, affording the corresponding products in good yields. This method did not only enrich scope of the Au(I)/Au(III) system, but also provided an effective way to synthesis β-substituted a,β-unsaturated y-butyrolactone which is an important unit of natural products.