Perovic Milena, Aloni Sapir Shekef, Zhang Wuyong, Mastai Yitzhak, Antonietti Markus, Oschatz Martin
Department of Colloid Chemistry, Max-Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany.
Department of Chemistry and the Institute of Nanotechnology, Bar-Ilan University, Ramat-Gan 5290002, Israel.
ACS Appl Mater Interfaces. 2021 May 26;13(20):24228-24237. doi: 10.1021/acsami.1c02673. Epub 2021 May 12.
Chiral separation and asymmetric synthesis and catalysis are crucial processes for obtaining enantiopure compounds, which are especially important in the pharmaceutical industry. The efficiency of the separation processes is readily increased by using porous materials as the active material can interact with a larger surface area. Silica, metal-organic frameworks, or chiral polymers are versatile porous materials that are established in chiral applications, but their instability under certain conditions in some cases requires the use of more stable porous materials such as carbons. In addition to their stability, porous carbon materials can be tailored for their ability to adsorb and catalytically activate different chemical compounds from the liquid and the gas phase. The difficulties imposed by the functionalization of carbons with chiral species were tackled in the past by carbonizing chiral ionic liquids (CILs) together with a template to create pores, which results in the entire body of a material that is built up from the precursor. To increase the atomic efficiency of ionic liquids for better economic utilization of CILs, the approach presented here is based on the formation of a composite between CIL-derived chiral carbon and a pristine carbon material obtained from carbohydrate precursors. Two novel enantioselective carbon composite materials are applied for the chiral recognition of molecules in the gas phase, as well as in solution. The enantiomeric ratio of the l-composite for phenylalanine from the solution was (L/D) = 8.4, and for 2-butanol from the gas phase, it was (S/R) = 1.3. The d-composite showed an opposite behavior, where the enantiomeric ratio for phenylalanine was (D/L) = 2.7, and for 2-butanol from the gas phase, it was (R/S) = 1.3.
手性分离、不对称合成与催化是获得对映体纯化合物的关键过程，这在制药行业尤为重要。通过使用多孔材料作为活性材料，可轻松提高分离过程的效率，因为活性材料能与更大的表面积相互作用。二氧化硅、金属有机框架或手性聚合物是在手性应用中已确立的通用多孔材料，但它们在某些情况下的不稳定性有时需要使用更稳定的多孔材料，如碳材料。除了稳定性外，多孔碳材料还可根据其从液相和气相中吸附和催化活化不同化合物的能力进行定制。过去，通过将手性离子液体（CILs）与模板一起碳化以形成孔隙来解决碳材料用手性物种功能化所带来的困难，这导致材料的整个主体由前体构建而成。为提高离子液体的原子效率以更好地经济利用CILs，本文提出的方法基于CIL衍生的手性碳与由碳水化合物前体获得的原始碳材料之间形成复合材料。两种新型对映选择性碳复合材料被应用于气相以及溶液中分子的手性识别。来自溶液的l - 复合材料对苯丙氨酸的对映体比例为（L/D） = 8.4，对气相中的2 - 丁醇，其对映体比例为（S/R） = 1.3。d - 复合材料表现出相反的行为，其中对苯丙氨酸的对映体比例为（D/L） = 2.7，对气相中的2 - 丁醇，其对映体比例为（R/S） = 1.3。
