Synthesis And Catalytic Performance Of Asymetric Counteranion-directed Catalysis

In the field of asymmetric catalytic research, developing asymmetric catalyst with highactivity and enantioselectivity is an important task to obtain enantiopure compounds. Atpresent, for making good catalyst, the development of new asymmetric catalytic reactionsbased on new concept is totally desired. The wide use of chiral Br nsted acids in theasymmetric catalysis makes chiral anionic become favorable in asymmetric catalyticresearch, and the reports of chiral anionic applications in asymmetric catalytic haveincreased quickly these years. In the mode of chiral anionic catalysis, the ionic chiralcatalyst reacts with the achiral substrate to form a chiral ion-pair as intermediate, whichtransfer the stereochemical information to the product. The mode of catalysis was termedas asymmetric counteranion-directed catalysis (ACDC). Recently, the asymmetriccounteranion-directed catalysis becomes the new strategy for asymmetric catalyst design. Asymmetric counteranion-directed catalysis has developed rapidly in the last ten years,however, the categories of chiral anionic and the types of the reaction they catalyzed arefew due to the study of its catalytic mechanism are not yet mature. Therefore, thedevelopment of asymmetric counteranion-directed catalysis faces many challenges as wellas great potential. To obtain chiral anion with novel structure, high activity,enantioselectivity and widely applicable reaction types, we designed several asymmetriccounteranion-directed catalysises and studied their catalytic performence in asymmetricalkylation and hydrogenation. Our work includes several aspects as follows:1. We firstly designed and synthesized asymmetric counteranion phase transfer catalystsbased on D-camphor sulfonic acid and applied in asymmetric alkylation of iminesdiphenyl glycine tert-butyl ester. We used D-camphor sulfonic acid anion to replace thechloride ion in the quaternary ammonium salt of cinchinine benzyl chloride, obtainedchiral cation-chiral anion phase transfer catalyst58. Catalyst58was applied to the phasetransfer alkylation reaction of the imines diphenyl glycine tert-butyl ester, gainedmoderate enantioselectivity (59%ee). We synthesized achiral N-methyl indoline benzylbromide quaternary ammonium salt, and used D-camphor sulfonic acid anion to replacethe bromide ion, obtained achiral cation-chiral anion phase transfer catalyst59. Catalyst59was applied to the phase transfer alkylation reaction of the imines diphenyl glycinetert-butyl ester, obtained lower enantioselectivity (4.3%ee). The results of preliminaryexperiment showed that the designed asymmetric counteranion phase transfer catalysts cannot induce enantioselectivity in asymmetric alkylation of imines diphenyl glycinetert-butyl ester.2. We established the general method which use the Suzuki coupling as the key step tosynthesize3,3-diary BINOLs with high yield. We synthesized six kinds of3,3’-substitutedbinaphthol (69a-f) by this method, the total yields were31-46%from binol. It has theadvantages of conciseness, mild reaction conditions, low cost, satisfactory yield and goodreproducibility. Further more, we synthesized three chiral phosphoric acids based onskeleton BINOL, the yield of the two steps were53-77%.3. Chiral phosphoric acids were changed into silver salt and exchanged ion with achiral metal catalysts formed ion pairing catalysts, applied for asymmetric hydrogenation ofN-acetyl cinnamic acid and itaconic acid ester. The results showed that these new kindcatalysts can ctalyze the hydrogenation of itaconic acid ester.