以廉价易得的方酸为原料,通过酯化,再与L-脯氨醇发生氨解反应,得到具有C2对称结构的手性L-脯氨醇方酰胺(分子式:C14H20N2O4),两步反应总收率67.5%.其结构经FT-IR、1 H NMR、13 C NMR、ESI-HRMS以及X-射线单晶衍射进行确证.该晶体属于斜...以廉价易得的方酸为原料,通过酯化,再与L-脯氨醇发生氨解反应,得到具有C2对称结构的手性L-脯氨醇方酰胺(分子式:C14H20N2O4),两步反应总收率67.5%.其结构经FT-IR、1 H NMR、13 C NMR、ESI-HRMS以及X-射线单晶衍射进行确证.该晶体属于斜方晶系,P212121空间群,晶胞参数:a=0.807 04(12)nm,b=0.901 36(13)nm,c=2.059 6(3)nm,α=β=γ=90.00°,V=1.498 2(4)nm3,Z=4,Dc=1.323g·cm-3,μ=0.100 mm-1,F(000)=640,最终残差因子R1=0.042 9,wR2=0.103 9.展开更多
The condensation of 4-bromobenzaldehyde with 2-ethoxycarbonyl-3,4-dimethylpyrrole gave Compound 3,which after hydrolyzation,was converted to the corresponding diacid 4.Six bis(oxazoline)compounds were synthesized dire...The condensation of 4-bromobenzaldehyde with 2-ethoxycarbonyl-3,4-dimethylpyrrole gave Compound 3,which after hydrolyzation,was converted to the corresponding diacid 4.Six bis(oxazoline)compounds were synthesized directly by the diacid reacting with chiral aminoalcohols.展开更多
The geometries and electronic spectra of a series of N-protonated corroles, including unsub- stituted H4Cor＋ and meso-triaryl substituted H4TPC＋, H4TpFPC＋, and H4TdCPC＋, were theoretically studied with density fun...The geometries and electronic spectra of a series of N-protonated corroles, including unsub- stituted H4Cor＋ and meso-triaryl substituted H4TPC＋, H4TpFPC＋, and H4TdCPC＋, were theoretically studied with density functional theory （DFT）. The results indicate that all these compounds have two conformers, one with C2 symmetry （denoted as Sl） is more stable than the other （denoted as $2, C1 symmetry） by 15.8-18.5 kJ/mol. The corrole macrocycles of these compounds show significant out-of-plane deformation. The enantiomerizations of the chiral S1 conformers were found to be a multi-step process with the $2 conformers as the intermediates. Electronic absorption spectra and electronic circular dichroism （ECD） of these compounds were calculated with time-dependent DFT. In comparison with H4Cor＋, the UV- Vis absorptions of meso-triaryl species are significantly red-shifted and their Q bands are enhanced due to the π-π conjugation between the aryl and corrole rings. Several neighboring electronic transitions were calculated with opposite signs in rotatory strengths, suggesting that ECD spectroscopy may be a useful tool in studying the electronic transitions of these compounds.展开更多
文摘The condensation of 4-bromobenzaldehyde with 2-ethoxycarbonyl-3,4-dimethylpyrrole gave Compound 3,which after hydrolyzation,was converted to the corresponding diacid 4.Six bis(oxazoline)compounds were synthesized directly by the diacid reacting with chiral aminoalcohols.
文摘The geometries and electronic spectra of a series of N-protonated corroles, including unsub- stituted H4Cor＋ and meso-triaryl substituted H4TPC＋, H4TpFPC＋, and H4TdCPC＋, were theoretically studied with density functional theory （DFT）. The results indicate that all these compounds have two conformers, one with C2 symmetry （denoted as Sl） is more stable than the other （denoted as $2, C1 symmetry） by 15.8-18.5 kJ/mol. The corrole macrocycles of these compounds show significant out-of-plane deformation. The enantiomerizations of the chiral S1 conformers were found to be a multi-step process with the $2 conformers as the intermediates. Electronic absorption spectra and electronic circular dichroism （ECD） of these compounds were calculated with time-dependent DFT. In comparison with H4Cor＋, the UV- Vis absorptions of meso-triaryl species are significantly red-shifted and their Q bands are enhanced due to the π-π conjugation between the aryl and corrole rings. Several neighboring electronic transitions were calculated with opposite signs in rotatory strengths, suggesting that ECD spectroscopy may be a useful tool in studying the electronic transitions of these compounds.
