新型纤维素衍生物手性固定相的制备及其对几种对映异构体的高效液相色谱分离

合成了一种经环十二烷修饰的纤维素酯，将其涂敷于小粒径的氨丙基化硅胶（APS）上，制备出高效液相色谱手性固定相，以正己烷、异丙醇为流动相拆分了2-对氯苯基丙腈、1-对氟苯基乙醇、1-对叔丁基苯氧基-2-丙醇、2-对氯苯基辛腈及三唑醇等5种外消旋对映体，并考察了流动相中异丙醇含量对分离效果的影响。     

Application of the chiral base desymmetrisation of imides to the synthesis of the alkaloid jamtine and the antidepressant paroxetine

The synthesis of the alkaloid jamtine and the antidepressant paroxetine have been addressed by a strategy involving asymmetric desymmetrisation of prochiral imides by a chiral lithium amide base. A short reaction sequence, starting with a cyclohexane fused succinimide, led to the structures originally reported for the alkaloid jamtine and its derived N-oxide. The structures synthesised are shown not to correspond with those originally reported. A second sequence involves desymmetrisation of a 4-arylglutarimide, and provides a short enantioselective synthesis of the drug substance paroxetine.     

新的手性配体促进的二芳基二酸和联萘酚的不对称合成

由手性配体α-D-葡萄糖衍生物5，6，7以及薄荷醇（8）和葑醇（9），经 Ulmann偶联反应得到光学活性的（R）－和（S）－6，6′－二硝基联苯－2，2′－ 二甲酸（4a),(R)-6,6′-二甲基联苯－2，2′-二甲酸（4b),(R)-1,1′－联萘－2 ，2′－二甲酸（13）。以三个手性膦酰胺16，17，18和CuCl组成的手性络合物为 催化剂，通过2－萘酚直接氧化偶联得到（S）－2，2′－联萘酚（15）。产物4， 13，15具有中等ee值的光学活性。     

一种新的环糊精衍生物手性固定相的合成及其在对映异构体过量值测定中的应用

 以 β 环糊精为原料 ,合成了一种新的环糊精衍生物 2 ,6 二 O 苄基 3 O 戊酰基 β 环糊精 ,用核磁氢谱和红外光谱对产物进行了表征 ,并将所得环糊精衍生物用作毛细管气相手性固定相制备成柱 ,用于 2 ,4 二氯苯乙酮的不对称催化氢化产物 2 ,4 二氯苯乙醇和反式 2 己烯醇的Sharpless环氧化产物 反式 3 正丙基环氧乙烷甲醇的对映异构体过量值 (e.e .值 )测定和催化反应评价 ,取得了很好的结果。     

Trifluoromethylated amino alcohols as chiral ligands for highly enantioselective Reformatsky reaction

The enantioselective Reformatsky reaction of PhCHO was achieved by the use of trifluoromethylated amino alcohols as chiral ligands to afford the corresponding optically active β-hydroxy ester with up to 90% ee.     

X-ray structure and circular dichroism of pure rotamers of bis[guanosine-5'-monophosphate(-1)](N,N,N',N'-tetramethylcyclohexyl-1,2-diamine)platinum(II) complexes that have R,R and S,S configurations at the asymmetric diamine

The use of a sterically hindered diamine ligand (Me(4)DACH) has allowed for the first time, the isolation and characterization, both in the solid state (X-ray crystallography) and in solution (circular dichroism), of pure DeltaHT rotamers of [Pt(Me(4)dach)(5'-GMP)(2)] (compounds 1 and 2 for R,R and S,S configurations of the Me(4)DACH ligand, respectively). Comparison of the CD spectra obtained for each rotamer, which differ only in the chirality of the Me(4)DACH ligand (R,R or S,S) or in the chirality of the HT conformation (Delta or Lambda), allowed us to conclude that, in the 200-350 nm range, the contributions to the overall CD spectrum that stem from diamine chirality and diamine-induced chirality of platinum d--d transitions or from sugar chirality are negligible relative to the exciton chiral coupling that occurs for pi-pi* transitions of the cis guanines. Accurate molecular structures of 1.10 D(2)O and 2.14 D(2)O (conventional crystallographic agreement indexes R(1) convergent to 2.07 % and 2.18 %, respectively) revealed that the crystallized rotamers have a DeltaHT conformation that is in agreement with all previously reported X-ray structures of [Pt(diamine)(nucleos(t)ide)(2)] complexes. This conformation allows the 5'-phosphate to be located in proximity to the Me(4)DACH ligand so that (P)O...HC(N) hydrogen-bond interactions exists in both complexes. For both structures, the canting of the guanine planes on the coordination plane is right-handed (R; canting angle (Phi) of 80.9 degrees and 73.2 degrees, respectively); this indicates that the canting direction is driven by the HT conformation chirality (Delta for both compounds) and not by the chirality of the carrier ligand (different for the two compounds). Density functional theory analysis of the conformational space as a function of Phi indicated a good agreement between the computed and experimental structures. The increase in energy for Phi values below 65 degrees and 55 degrees (for 1 and 2, respectively) is mainly due to the short intramolecular contacts between C(8)H and the cis N-Me groups on the same side of the platinum coordination plane.     

手性液晶掺杂剂（S）—4‘—辛氧基—4—（2—酰氧基—丙氧基）联苯的合成

手性液晶掺杂剂（Ｓ）┐４┐辛氧基┐４┐（２┐酰氧基┐丙氧基）联苯的合成马汝建李培荣国斌＊（华东理工大学化学系上海２００２３７）关键词铁电液晶材料，手性液晶掺杂剂，合成，手征性１９９７－０２－０３收稿，１９９７－０８－０７修回铁电液晶显示器所用的材料...     

Siliceous materials with the surface polymer layer composed of dextran-polyimine mixture as column packings for liquid chromatography

Summary Forming a polymer layer on the surface of siliceous materials is one of the methods for protecting the silica skeleton from dissolution in alkaline mobile phases as well as eliminating the negative influence of silanol groups on separated molecules e.g. proteins. Polysaccharides, especially their derivatives bearing amine groups, can play the role of the surface layer. This paper discusses the possibilities of preparing such a layer by cross-linking a dextran-polyimine mixture (rather than the traditionally used DEAE-dextran) deposited on the surface of the solid material. The results presented prove the utility of synthesized materials as supports for affinity ligands in high performance affinity chromatography or as supports for complexed metal ions in ligand-exchange chromatography. The properties of the sorbents with a polymer layer can be changed both by the composition of the cross-linked mixture and by chemical modification.     

Carbonat-isostere Anionen [SnX3]5− in den Verbindungen Rb6[SnX3]O0,5 und Cs6[SnX3]O0,5 mit X = As,Sb und Bi

Carbonate Isostructural Anions [SnX₃]^5? in the Compounds Rb₆[SnX₃]O_0.5 and Cs₆[SnX₃]O_0.5 with X = As, Sb, and Bi The metallic shining compounds Rb₆[SnX₃]O_0.5 and Cs₆[SnX₃]O_0.5 with X = As, Sb, and Bi were prepared from the melt starting from adequate mixtures of the elements and SnO₂. They crystallize in the hexagonal system (space group P6₃/mmc, No. 194, Z = 2) with the lattice constants mentioned in ?Inhaltsübersicht”?. In the structures of the isotypic compounds tin and the main group(V) elements build up trigonal planar anions [SnX₃]^5? with X = As, Sb, and Bi isostructural to the carbonate anion, oxygen forms isolated O^2? ions. The bond lengths Sn? X are significantly shortened with respect to the sums of Pauling covalent radii. The atoms of the units [SnX₃]^5? are coordinated by alkali metal cations forming trigonal prisms and the O^2? anions occupy octahedral holes.     

Stable silica gel-bound crown ethers. Selective separation of metal ions and a potential for separations of amine enantiomers

Silica gel-bound crown ethers and aza macrocycles have been synthesized with the attaching arm connected to the carbon framework of the macrocycles. The interactions of these bound macrocycles with cations are almost identical to those involving the analogous free macrocycles. This has allowed for predictable cation separation, concentration, and removal processes to be performed on a small scale. Quantum mechanical calculations and NMR measurements indicate that similarly bound chiral macrocycles will be capable of use in separating chiral organic amines.Dedicated to the memory of Professor James J. Christensen who died on 5 September 1987.