Combinatorial and Biomimetic Approach on Asymmetric Catalysis for the Synthesis of Ferroelectric Liquid Crystals

摘要

During the funding period, we have made significant progress both in the developing new methods for asymmetric synthesis and discovering new liquid crystal materials. Over a dozen of papers have been published or in press in several journals (J. Am. Chem. Soc., J. Org. Chem. and Tetrahedral Letter) and three have been submitted for publication. We have developed a chiral toolbox with a large set of chiral ligands for asymmetric catalysis. These includes helical ligands, chiral monophosphines, chiral tridentate ligands and novel chiral bidentate phosphines with rigid backbones. Excellent activities and enantioselectivities (up to 99 % ee) have been observed in many asymmetric reactions such as hydride transfer reaction, hydrogenation, alkylation of aldehydes, cycloaddition and allylic alkylation. Seven patents have been filed and several companies (Catalytica and Pfizer) have licensed this technology for the production of chiral molecules in industrial scales. Using these methods and other organometallic methodologies, we have made a number of chiral liquid crystals and related materials. We are developing high polarization materials as candidates of novel ferroelectric liquid crystals. The viscosity of a diphenyl- diacetylene liquid crystals is far lower than the corresponding quadra-phenyl liquid crystals. We have synthesized chiral liquid crystals using this conjugated backbone (diphenyl diacetylene). We also plans to change the arrangement of the phenyl-acetylene modules and these changes could alter the physical properties of liquid crystals in useful ways (e.g., absorption efficiency of Laser lines). This research is carried out in collaboration with Professor I. C. Khoo in Department of Electrical Engineering at Penn State University. The research collaboration with Professor Khoo has resulted in excellent laser optical limiting materials.