查询词典 asymmetric

We examine the asymmetric Aldol reaction with cyclohexanone and aldehyde using tunable and bifunctional organocatalysts in aqueous media.

相反，尽管在盐水溶液中的反应效果可以比在水中的效果要好，但是较少有使用盐水溶液作为反应介质的报道。

We found that when acetone was used as solvent, in the presence of TFA, cis-4-pyrrodin-1-yl-L-proline could catalyze the direct asymmetric aldol reaction between acetone and 4-nitrobenzaldehyde with 84% ee.

研究发现，该催化剂以丙酮为溶剂时，加入催化剂等当量的三氟乙酸可以较好的催化丙酮与对硝基苯甲醛之间的直接不对称Aldol反应，得到84%的ee值。

The catalytic effects of 1a and 1b on the intermolecular direct asymmetric aldol reaction were evaluated in organic solvents and in water respectively. The activity of 1a was higher than that of 1b.

研究了1a和1b分别在有机相和水中催化分子间直接不对称Aldol反应的性能，发现具有较长烷基链的1a比具有较短链的1b催化活性高。

The key reaction included Aldol condensation,CBS asymmetric reduction and Mitsnobu reaction.

合成过程中的关键反应为Aldol缩合，CBS不对称还原，Mitsnobu反应等。

The purpose of the above mentioned obligations is to relieve the asymmetric information, avoid moral hazard caused by the adhesive, aleatory and continuity nature of insurance contract.

上述义务的根本目的在于缓解双方的信息不对称，避免保险合同的附合性、射幸性以及连续性所带来的道德风险。

It is considered, inter alia, as a necessary counterbalance to asymmetric market access in international trade.

特别，作为在国际贸易过程中的非对称的市场准入的一个必要平衡物，它被考虑。

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。

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。

Lightfoot et al have developed one of these iridium-based systems for the stereocontrolled synthesis of lilial by asymmetric reduction of an allyl alcohol and subsequent oxidation of the alcohol.

Lightfoot等发展了一种基于铱的系统，通过烯丙醇和第二阶段酒精氧化的不对称还原，用来进行铃兰醛的立体控制合成。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失