对映体

These ligands were found to be very effective in construction of quaternary carbon centers by using asymmetric allylic alkylation.

这类配体在前手性亲核试剂的不对称烯丙基化构筑手性季碳中心的反应中，显示了较好的反应活性及对映选择性。

The ligands were found to be effective in palladium-catalyzed asymmetric allylic alkylation to construct chiral quaternary carbon center.

这类配体在前手性亲核试剂的不对称烯丙基化构筑手性季碳中心的反应中，显示了较好的反应活性及对映选择性。

When ligands with only planar chirality were used in the two model reactions (allylic alkylation and amination), comparatively high enantioselectivities were obtained.

令人鼓舞的是设计合成的只具有平面手性的膦氮配体，也可以取得中等到良好的对映选择性。

Secondly, 11 chiral ligands containing BINOL and its derivatives werescreened in the asymmetric HDA reaction between Brassard diene withbenzaldehyde. The results revealed that-BINOL shows higherenantioselectivity and reactivity than the others.

其次将 11 个二齿配体 BINOL 及其衍生物用于 Brassard 二烯与苯甲醛的不对称 Hetero-Diels-Alder 反应，结果表明，-BINOL 表现出相对较好-i-范谦四川大学博士论文的反应活性和对映选择性。

The results show that catechin stereoisomers possess the same fragmentation pathways and cannot be differentiated even in MS spectra.

发现儿茶素对映异构体间具有相同的质谱裂解途径，多级质谱无明显区别。

Diastereomers of cinchonine and cinchonidine were separated in pressure-assisted capillary electrochromatography mode, and the resulted separation efficiency was much higher than that obtained in high performance liquid chromatography.

采用压力辅助电色谱模式拆分了非对映异构体辛可宁和辛可尼丁，其柱效远高于其在HPLC中拆分的结果。

At present, studies on and applications of chiral diamine s have been regarded as one of the most remarkable fields in catalytic asymmetric reactions.

手性二胺作为具有良好催化活性和对映选择性的手性配体或手性辅助剂，在多种催化不对称反应中已经得到广泛应用，并取到了很好的研究成果。

Objective: To develop a method for purity test and enantioseparation of ephedrine levorotatory by capillary electrophoresis.

目的：建立左旋麻黄碱中对映异构体杂质检查的毛细管电泳方法。

The chiralMn complexes, especially Jacobsenscatalyst, display high enantioselectivity for asymmetric epoxidation of conjugated cis-di-, tri-and some tetrasubstituted prochiral alkenes in the NaClO biphasic system, but the epoxidationreaction generally requires a long reaction time even in the presence of an axial ligand.

在NaClO两相体系中，手性Mn配合物，尤其是Jacobsen催化剂，对共轭顺式二取代、三取代和部分四取代烯烃的不对称环氧化具有高的对映选择性，然而即使存在轴向配体，环氧化反应也通常需要长的反应时间。

The chiralMn complexes, especially Jacobsen\'scatalyst, display high enantioselectivity for asymmetric epoxidation of conjugated cis-di-, tri-and some tetrasubstituted prochiral alkenes in the NaClO biphasic system, but the epoxidationreaction generally requires a long reaction time even in the presence of an axial ligand.

在NaClO两相体系中，手性Mn配合物，尤其是Jacobsen催化剂，对共轭顺式二取代、三取代和部分四取代烯烃的不对称环氧化具有高的对映选择性，然而即使存在轴向配体，环氧化反应也通常需要长的反应时间。

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。