对映体

SAA ligand Lh could induce asymmetric addition of terminal alkyne to aldehydes without using air-sensitive Ti4and expensive Zn2.with good result of high yield (up to 99%) and good enantioselectivities (up to 84%ee).

将SAA配体Lh应用于在无Ti_4和Zn_2的条件下促进端基炔对醛的不对称加成反应中，反应的收率普遍较高，最高达99%，对映体选择性高达84%ee。

" Racemate: Mixture of equal quantities of two enantiomers, substances whose molecular structures are mirror images of one another."

外消旋体：两种分子结构互为镜像的对映体的等量混合物。

Pharmacological interactions between the enantiomers may happen when a chiral drug w as used as its racemate .

当手性药物以外消旋体供药用时，其对映体间就可能发生药效学和药代动力学的相互作用。

E. value of productions were detected by high performance liquid chromatography. Results The chiral aminoalcohol ligand compound Ⅰ can promote the asymmetric allylation of acylhydrazones and the yield was 57%; The highest values of e. e. obtained for this reaction was 22%.

结果 手性氨基醇配体化合物Ⅰ能够促进烯丙基三氯硅烷和酰腙的烯丙基化加成反应，在它的辅助作用下，烯丙基化加成产物的产率可达到57%，对映体过量值最高达到22%。

For the first time, enantiomers of C2-symmetric 1,1 -spirobiindane-7,7'-diol were resolved with crude menthyl chloroformate by phase-transfer catalysis in the presence of tetrabutylammonium bromide. The reaction was carried out at 0℃-rt. The diastereomers of SPINOL bis-menthyl carbonate can be separated by simple crystallization using alcohol. The hydrolysis of the diastereomers was carried out via aqueous NaOH/EtOH solution.

首次通过相转移催化的方法对螺双二氢茚二酚进行了有效的拆分，用L--氯甲酸薄荷醇酯做拆分剂，以四丁基溴化铵为催化剂在0℃-室温下进行酯化反应生成非对映体衍生物，以乙醇作溶剂，通过重结晶的方法分离衍生物，在水-乙醇混合溶剂条件下，用强碱NaOH或KOH分别水解，制得相应的光学纯度大于99%ee的两个异构体SPINOL，其中总收率：--SPINOL，78.2%；--SPINOL，80.6%。

The effect of silicon atom in substrate on the reaction rate and the stereoselectivity of enzymatic reactions was revealed by comparison of horse liver alcohol dehydrogenase-catalyzed stereoselective dehydrogenation of the three isomers of acetyltrimethyl propanone and their carbon analogues in aqueous/organic biphasic systems.

本项目通过对比在水－有机溶剂两相系统中，马肝醇脱氢酶催化三甲基硅烷丙酮的三个异构体及其碳类似物的光学选择性脱氢反应，揭示了底物中的硅原子对酶反应速度、立体选择性的影响规律，成功地合成了高对映体纯度的手性有机硅醇，并实现了辅酶的再生。

SAA ligand Lg could catalyze asymmetric addition of phenylacetylene to unactivated aromatic ketones in high yields (up to 83%) and high enantioslectivities (up to 83%ee).

SAA配体Lg用于催化炔基锌对未活化酮的不对称加成反应，对于芳香酮的催化反应，收率可达83%，对映体选择性可达83%ee。

Chiral SalanCrX complexesa saturated version of SalenCr(ⅢX are designed,and in conjunction with an ionic quaternary ammonium salt or organic strong base can efficiently catalyze the asymmetric,regio-and stereoselective alternating copolymerization of CO_2 with rac-PO at mild conditions to afford isotactic-enriched polycarbonates with～95%head-to-tail linkages and moderate enantioselectivity.

本论文在Salen构型配体的基础上，设计合成了一系列手性Salan型铬配合物，并将其与季铵盐/有机强碱组成亲电-亲核双组分催化体系，在室温下可以有效的催化CO_2和环氧丙烷的不对称交替共聚反应，实现了CO_2和环氧丙烷的不对称交替共聚反应的区域和立体化学控制，得到95%的头尾连接单元和中等光学纯度(对映体过量值ee%≈70%)的全同结构的聚碳酸酯。

Separation of racemic mixtures of thirty-eight secondary aromatic alcohols and arylethanediols with different substituting group was achieved with HPLC by using Chiralcel OD and Chiralcel LJ as chiral stationary phase and hexane/2-propanol mixtures of different ratios as eluents. The chromatographic parameters of these racemates on OD and OJ columns were examined.

在ChiralcelOD和ChiralcelOJ两支多糖类手性固定相上，以各种不同配比的正己烷-异丙醇为洗脱剂对38种带有不同取代基的芳香仲醇及芳香乙二醇类手性化合物的对映体进行拆分，考察了这些外消旋体在这两支手性柱上的色谱行为。

More than 50% of the commercial drugs available worldwide have stereogenic centers and most of them are marketed as racemates at present.

目前，大多数药物以外消旋体给药为主，而以光学纯的对映体给药是大多数手性药物的发展趋势。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。