DFT Study on the (S)-Proline-catalyzed Direct Aldol Reaction between Acetone and 4-Nitrobenzaldehyde

DFT/6-31G^＊ calculations were applied to study the direct aldol reaction between acetone and 4-nitrobenzaldehyde catalyzed by （S）-proline. Four transition states associated with the stereo-controlling step, corresponding to syn and anti arrangements of methylene moiety related to the carboxylic acid group in enamine intermediate and re and si attacks to the aldehyde carbonyl carbon have been obtained. The solvent effect of DMSO was investigated with polarized continuum model. The computed energies of transition states reveal the stereo-selectivity of the reaction.

N-BOC-L-色氨酸分子印迹聚合物的手性拆分

以分散聚合法制备的聚苯乙烯微球为种子,采用单步溶胀悬浮聚合法,N-BOC-L-色氨酸为模板分子,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯为交联剂,在水相中成功制备了分子印迹聚合物微球,吸附实验表明,印迹聚合物对模板N-BOC-L-色氨酸有良好的吸附性,该聚合物作为液谱固定相,实现了模板与其对映体的快速基线分离。

N-Boc-L-2-乙酰哌啶的合成研究

采用4种方法完成了目标化合物的合成,通过实验比较,确定了两步合成、总收率>90%、可用于实验室大量制备的合成路线,并成功将此方法运用于N-Boc-L-2-乙酰吡咯烷的合成。

Highly Efficient Asymmetric Synthesis Usomg Organocatalyst Derived From(S)-proline

1 Results Much effort has been focused on organocatalytic asymmetric synthesis in these several years. We have already documented highly efficient organocatalytic asymmetric acylation of a wide variety of racemic alcohols and meso-diols catalyzed bya chiral 1,2-diamine derived from (S)-proline[1]. (S)-Homoproline seems to be a potentially interesting organocatalyst, but no examples using (S)-homoproline itself in asymmetric synthesis has been reported. We have accomplished an efficient and practical syn...

核壳结构Boc-氨基酸分子印迹分离介质的研究

将硅胶表面硅羟基与γ-(甲基丙烯酰氧)丙基三甲氧基硅烷反应合成具有CC端基的改性硅胶核,进一步以N-Boc-L-色氨酸为模板分子,采用分子印迹技术在改性后的硅胶表面包覆印迹聚合物,制备出核壳结构氨基酸分子印迹分离介质。这种印迹分离介质对模板N-Boc-L-色氨酸具有良好的吸附性,最大饱和吸附量可达到85.96 mg/g,印迹效率为70.67%,明显高于本体聚合法。采用新型分子印迹分离介质装填成高效液相色谱柱,实现了模板分子与其对映体的快速基线分离,分离度为1.64。

沙格列汀中间体甲酰胺甲磺酸盐的合成工艺

(1S,3S,5S)-2-氮杂二环己烷-3-甲酰胺甲磺酸盐是合成沙格列汀的关键中间体。以N-Boc-L-焦谷氨酸乙酯为初始原料,依次经过还原、消除、水解、氨解、环丙烷化以及成盐得到目标化合物。工艺收率高、操作简单稳定连续性强,适合工业化生产。