Asymmetric total synthesis of FR65814, a novel immunosuppressant

학위논문(박사)--서울대학교 대학원 :약학과 약화학 전공,2004.Docto

Min JaeKi

학위논문(석사)--아주대학교 일반대학원 :분자과학기술학과,2009. 2A highly active catalytic system for CO2/(propylene oxide) copolymerization was prepared based on the concept of a system containing a Lewis acidic metal center and quarternary ammonium salts units. The catalytic system showed high activity (TON >20000; TOF >20000 h-1) even at high temperature and high [epoxide]/[catalyst] ratio and selectively producing a very high molecular-weight copolymer (Mn, 300,000). The catalyst can be easily separated by filtration through a short pad of silica gel to obtain polymer containing negligible amounts of metal residue (1-2 ppm). The separated catalyst can be reused without significant loss in catalytic performance.Table of Contents Chapter 1. Highly Active and Recyclable Catalytic Systems for CO2/(Propylene Oxide) Copolymerization.......................................................1 1. Introduction............................................................2 2.Result and Discussion.............................................6 2.1SynthesisandCharacterization.................................6 2.2polymerizationstudies............................................8 2.3Catalyst Recovery Strategy....................................11 2.4 Conclusion.........................................................17 3. Experiment Section...............................................17 4. Reference............................................................33 5. Figures................................................................36 Chapter 2. Efficient Synthetic Route for A Highly Active Catalyst for CO2/(Propylene Oxide) Copolymerization...................59 1. Introduction..........................................................60 2. Result and Discussion...........................................61 3. Experiment Section...............................................65 4. Reference............................................................70 5. Figures................................................................72Maste