Substituted-benzyl-containing N-methyl-ephedrinium derivatives (BMEP), prepared from the highly-accessible (1,2)- or (1,2)-ephedrine alkaloids, have been found to act as efficient structure-directing agents for the synthesis of chiral zeolite GTM-4 with –ITV framework structure, promoting the enantio-enrichment in one of the chiral crystalline polymorphs as a function of the organic handedness. Results of a systematic variation of substituents in the benzyl ring attached to the ephedrine core (with methyl-, fluoro- or chloro-groups in the different positions of the aromatic ring) revealed that F-containing SDAs brought about an improvement in the structure-directing ability toward the –ITV framework, giving asymmetric zeolite acid-catalysts that yielded notable enantiomeric excesses in the range of 40–45 % for the -stilbene oxide ring-opening with 1-butanol. Interestingly, the incorporation of a methyl group in ortho-position (oMBMEP) had a double positive effect: on the one hand, this SDA prevented the crystallization of the competing BEC phase, allowing the crystallization of the -ITV structure at higher temperature and with higher crystallinity, and on the other, it drove to GTM-4 asymmetric catalysts that yielded enantiomeric excesses up to 60 %, resulting in the chiral GTM catalysts with the best enantioselective properties found so far. Remarkably, our catalytic results show the same chiral activity (in terms of zeolite handedness) for GTM-4 materials prepared from benzyl-containing (1,2)-N-methyl-pseudoephedrinium (BMPS) and (1,2)-N-methyl-ephedrinium (BMEP) derivatives, thus suggesting that the host-guest transfer of chirality during crystallization with these chiral organic aromatic agents is imposed by the absolute configuration of the C1 atom to which the OH group is attached. The relatively high enantiomeric excess of 60 % achieved, combined with the high accessibility of the ephedrine chiral precursors used for the synthesis that enables the production of both crystalline handedness of the –ITV framework, bring these materials closer to a potential application as heterogeneous asymmetric catalysts for the synthesis of chiral compounds of interest.

中文翻译：

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由易于获得的麻黄碱生物碱制备的具有改进的对映选择性催化性能的手性沸石材料

含取代苄基的 N-甲基麻黄衍生物 (BMEP) 由易于获取的 (1,2)- 或 (1,2)-麻黄碱生物碱制备而成，已被发现可作为有效的结构导向剂合成具有 –ITV 骨架结构的手性沸石 GTM-4，促进一种手性晶体多晶型物的对映体富集，作为有机手性的函数。与麻黄碱核心相连的苄基环中取代基（在芳香环的不同位置上具有甲基、氟或氯基团）的系统变化的结果表明，含氟 SDA 带来了结构的改进-向-ITV骨架的定向能力，产生不对称沸石酸催化剂，在与1-丁醇的-二苯乙烯氧化物开环时产生显着的对映体过量，在40-45%的范围内。有趣的是，在邻位掺入甲基（oMBMEP）具有双重积极作用：一方面，这种 SDA 阻止了竞争性 BEC 相的结晶，从而允许 -ITV 结构在更高的温度下结晶，并且具有另一方面，它推动了 GTM-4 不对称催化剂的产生，其对映体过量高达 60%，从而产生了迄今为止发现的具有最佳对映选择性性质的手性 GTM 催化剂。值得注意的是，我们的催化结果显示，由含苄基的 (1,2)-N-甲基-伪麻黄鎓 (BMPS) 和 (1,2)-N- 制备的 GTM-4 材料具有相同的手性活性（就沸石旋向性而言）。甲基麻黄素 (BMEP) 衍生物，因此表明这些手性有机芳香剂结晶过程中手性的主客体转移是由 OH 基团所连接的 C1 原子的绝对构型决定的。相对较高的对映体过量率达到了 60%，再加上用于合成的麻黄碱手性前体的高可及性，能够产生 –ITV 框架的晶体旋向性，使这些材料更接近于作为非均相不对称催化剂的潜在应用用于合成感兴趣的手性化合物。