Chiral Porous Metal-Organic Frameworks as A Tunable Platform for Asymmetric Catalysis

在这项由化学系化学催化计划资助的项目中，芝加哥大学的林文斌教授正在开发将溶液催化转化为固相的新型固体催化剂。大多数商品化学品的生产使用固相催化剂，因为它们在化学使用和分离方面效率很高。某些重要的化学品目前只能在溶液中生产，因为合成它们的固相催化剂尚不清楚。这些过程通常需要大量的有机溶剂，而且可能相当浪费。在这项研究项目中，林教授正在合成基于金属-有机骨架(MOF)的新型固相催化剂，MOF是由有机分子和骨架片和金属原子作为连接点构建的材料。这种材料是多孔性的，使分子能够进出结构，通过定制金属原子连接位置，研究人员正在决定材料内可能发生的催化类型。通过将金属原子位的结构与已知的溶液相催化剂相匹配，研究人员正在创造能够执行类似的溶液相反应的MOF。该项目还整合了研究、培训和教育。参与研究项目的研究生和本科生正在学习重要的研究和沟通技能。林教授还与大学合作伙伴计划合作，接待芝加哥地区的高中生在实验室进行研究体验。林教授正在开发策略，以合成基于m-BINAP基元的新型手性MOF，并研究其作为不对称催化反应单位固体催化剂的活性。这方面的研究主要集中在：1)通过引入混合连接物来调节手性、多孔MOF的有效反应空间；2)探索MOF中富含稀土的金属不对称催化和有机催化；3)通过光活性多组分MOF组装实现不对称光催化；4)开发用于不对称串联催化的多功能MOF体系。与许多其他类型的多相不对称催化剂相比，准确地确定MOF结构的能力提供了明显的优势，因为MOF的催化活性/选择性可以使用一系列表征方法来近似，并通过使用定制的构建块来改变。MOF基单中心固体不对称催化剂有可能成为具有价格竞争力的多相催化剂，并在精细化学合成中得到应用。

In this project funded by the Chemical Catalysis Program of the Chemistry Division, Professor Wenbin Lin at the University of Chicago is developing new types of solid catalysts that translate solution phase catalysis into the solid phase. The production of most commodity chemicals utilizes solid phase catalysts due to their efficiency in chemical usage and separation. Certain important chemicals presently are only made in solutions because solid phase catalysts for their synthesis are not known. These processes usually require lots of organic solvents and can be quite wasteful. In this research project Professor Lin is synthesizing new classes of solid phase catalysts based upon metal-organic frameworks (MOFs), materials that are built from organic molecules and the framework pieces and metal atoms as the connecting points. The materials are porous which enables molecules to move in and out of the structures, and by tailoring the metal atom connection sites, the researchers are dictating the types of catalysis that can occur within the material. By matching the structures of the metal atom sites to known solution phase catalysts, the researchers are creating MOFs that can perform the analogous solution phase reactions. The project is also integrating research, training and education. Graduate and undergraduate students participating in the research project are learning important research and communication skills. Professor Lin is also partnering with the Collegiate Partner Program to host Chicago area high school students for a research experience in the laboratory.Professor Lin is developing strategies to synthesize novel chiral MOFs based upon m-BINAP motifs with large open channels and pores and to study their activity as single-site solid catalysts for asymmetric catalytic reactions. The studies are focusing on: 1) tuning the effective reaction space of chiral, porous MOFs through the inclusion of mixed linkers; 2) exploring earth-abundant metal asymmetric catalysis and organocatalysis within the MOFs; 3) realizing asymmetric photocatalysis via photoactive multicomponent MOF assemblies; and 4) developing multifunctional MOF systems for asymmetric tandem catalysis. The ability to determine MOF structures precisely provides distinct advantages over many other types of heterogeneous asymmetric catalysts, because the catalytic activities/selectivities of the MOF can be approximated using a range of characterization methods and altered through the use of tailor-made building blocks. MOF-based single-site solid asymmetric catalysts have the potential to become cost-competitive heterogeneous catalysts and find application in fine chemical synthesis.