Jocic reactions involve the reaction of trihalocarbinols with nucleophiles via 2,2-dichloroepoxides. Stereospecific versions with enantiomerically enriched trihalocarbinols are however rather uncommon. This is probably due to the very few methods of synthesising enantiomerically enriched trihalocarbinols. This thesis describes the development of a general route for synthesis of enantiomerically enriched trichlorocarbinols and their subsequent use in stereoselective Jocic reactions. Chapter 1 discusses the work towards developing a general route for the asymmetric transfer hydrogenation of trichloromethyl ketones. Initially a brief overview of stereoselective hydrogenation and the required forms of chelation is given. Following this, a detailed review of the known directing groups for asymmetric transfer hydrogenation reactions is provided before the report of the discovery that the trichloromethyl moiety may also be a strong directing group. Finally, the ability of trichloromethyl as a directing group for transfer hydrogenation reactions is explored. Chapter 2 opens with a summary of the reported mechanistic investigations into the Jocic reaction. Following this, a detailed review of the different nucleophiles used in both racemic and stereospecific Jocic-type reactions is given. Then, the current reported syntheses of enantiomerically enriched piperazin-2-ones, and related compounds, is discussed. Finally, the development of a general synthesis for these compounds is explored using amine nucleophiles in stereospecific Jocic-type reactions. Chapter 3 opens with a discussion of a publication which reports the enzymatic resolution of an allylic trichloromethyl acetate for the synthesis of its corresponding alcohol in high enantiomeric excess. Following this, the use of porcine liver esterase and Candida rugosa lipase are investigated for enzymatic resolutions with acetate derivatives of some of the trichlorocarbinols from in Chapter 1.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:635607 |
| Date | January 2014 |
| Creators | Perryman, Michael S. |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/66174/ |
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