二乙基锌

Synthesis of novel sulfonamide-prolinols and their application on the asymmetric addition of diethylzinc to benzaldehyde.

三、研究了脯氨酸衍生的新型手性磺酰胺-氨基醇的合成及其催化二乙基锌对苯甲醛的不对称加成反应 1。

The catalytic effects of 16a-e on the asymmetric addition of diethylzinc to benzaldehyde were evaluated, and it was found that they could promote the reaction with up to 63% yield and 27% ee.

研究了化合物16a-e催化二乙基锌对苯甲醛的不对称加成，发现16b-e可以催化该反应的进行，最高产率为63％，ee值27％。

A novel application of hydrolase as catalyst for the addition of diethylzinc to aromatic aldehydes is reported. Optimum conditions were screened out.

报道了水解酶催化二乙基锌与芳香醛的加成反应，对反应条件进行了优化。

Therelationship of the amount of catalyst and the ee% of product was seen to be negative nonlin-ear. Catalyst 3 was used in the enantioselective addition of diethylzinc to aromatic aldehydesand gave good results. The configuration of products was determined by the configuration ofthe catalysts' chiral carbon linked with hydroxy group. Using β- amino alcohols bearing only one chiral center as catalysts for the enantiose-lective addition were studied. D-N, N-dialkyl-2-amino butanol gave poor catalytic effect be-cause of their structure. The configuration of the product is the same as the catalyst. Anotherkind of β- amino alcohols - phenylglycine derivatives and valine derivatives have chiralcenter on the carbon linked with amino group. Catalyzed by-phenylglycine derivatives 6,7, 9, 10, the reactions gave satisfied results. The optical yields exceeded 80%.

在探讨了含有两个手性中心的β-氨基醇之后，选择了只有一个手性中心的β-氨基醇，一是手性中心为连羟基的手性碳原子：D-N，N-二烷基-2-氨基丁醇；二是手性中心为连氨基的手性碳原子：D-苯基甘氨酸衍生物和L-缬氨酸衍生物。D-2-氨基丁醇的催化效果不太好，这与其结构的空间位阻较小有关系，反应产物与连羟基手性碳构型一致；由苯基甘氨酸和缬氨酸出发合成五种β-氨基醇6-10，研究了不同ee％的-6作用下的二乙基锌-苯甲醛加成反应，发现该催化剂具有不对称放大效应；-7，9，lO的催化效果也比较令人满意，光学产率80％以上，所得产物构型与催化剂构型一致。

Previously, we reported chiral 2, 5-disubstituted pyrrolidine derivatives as chiral catalyst ligands in the reaction of diethylzinc with arylaldehydes. Very high yields and enationselectivities have been achieved in this asymmetric addition reaction.

我们小组以前合成的具有C〓-对称性的五员氮杂环类手性配体在二乙基锌和醛的不对称加成反应中取得了优良的结果。

Four new chiral sulfonamide alcohol s were synthesized from camphor and L-phenylalanine and their application to the enantioselective addition of diethylzinc to benzaldehyde was described.

由天然樟脑和-苯丙氨酸合成了4个新的手性磺酰胺醇，并对其在二乙基锌对苯甲醛的不对称加成中的催化性能进行了研究。

Four new chiral sulfonamide alcohols were synthesized from camphor and L-phenylalanine and their application to the enantioselective addition of diethylzinc to benzaldehyde was described.

由天然樟脑和-苯丙氨酸合成了4个新的手性磺酰胺醇，并对其在二乙基锌对苯甲醛的不对称加成中的催化性能进行了研究。

The preparation of a novel chiral sulfonamide alcohol derived from natural camphor and its application in the titanium tetraisopropoxide-promoted enantioselective addition of diethylzinc to benzaldehyde is described.

由天然樟脑合成了一个新手性磺酰胺醇，并对其在二乙基锌对苯甲醛的对映选择性加成中的催化性能进行了研究，获得了73%化学产率和

The Strecker reactions and the addition reactions with diethylzinc of imines in the presence of organophosphine were also studied.

发现在有机膦的参与下，多种亚胺的Strecker反应和普通亚胺与二乙基锌的加成反应都能顺利的进行。

Similarly, HMPA has theability to markedly affect the stereoselectivity of the tandem reaction.β-Aminoketones can be generated with high stereoselectivity (the ratio of trans-anti andtrans-syn is up to 94/6) when 4 equiv. of HMPA was used as the additive in THF.

其次，我们以二乙基锌来引发串联反应，发现HMPA对反应的选择性同样产生显著的影响，并通过在反应体系中加入4当量的HMPA，高立体选择性地得到了β-氨基酮类化合物(trans-anti／trans-syn一般为94／6)。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新