This thesis is divided into two sections. In Section I, the desymmetrisation of a <i>meso-</i>cyclic anhydride was described. However, the transformation requires extremely low temperatures (-55°C) and a long reaction time (96 h) in order to achieve high enantioselectivity, which is not feasible for transfer into a continuous flow system. Later on, the work turned to investigation of its application towards the synthesis of chiral cyclopentanes using new enabling technologies. In Section II, the enantioselective Michael addition of aldehydes to nitroethylene in flow was described. The process was successfully incorporated into a flow system (R2+ and R4 unit). Key to this organocatalytic process is the use of catalytic amounts of a diphenylprolinol silyl ether catalyst with acetic acid as co-catalyst. This is an efficient catalytic system that enables faster transformation (1-3 h) with high enantioselectivities (up to 98% <i>ee</i>). A study on a proposed enol mechanism for this catalytic process was also discussed. Both sections provide full experimental procedures as well as characterisation in support of the results described within this thesis.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:605607 |
| Date | January 2010 |
| Creators | Jin, X. |
| Publisher | University of Cambridge |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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