Reference: Scott A. Bentley, (2011). Asymmetric conjugate addition reactions. DPhil. University of Oxford.Citable link to this page:
This thesis is concerned with the asymmetric conjugate addition reactions of a range of chiral nucloeophiles.
Chapter 1 introduces the conjugate addition reaction as a valuable carbon-carbon and carbon-heteroatom bond forming reaction in organic chemistry, and explores the asymmet- ric conjugate addition of a range of chiral and achiral carbon and nitrogen nucleophiles to a range of acceptors.
Chapter 2 explores the use of the N-benzyl-N-(α-methylbenzyl)amino group as a chi- ral auxiliary, by employing the attempted conjugate additions of both N-benzyl-N-(α- methylbenzyl)hydrazine and N -benzyl-N -(α-methylbenzyl)hydroxylamine as chiral ammo- nia and water equivalents respectively.
Chapter 3 describes the asymmetric and stereoselective preparation of a range of 4,4- disubstituted isoxazolidin-5-ones from the conjugate addition of lithium (S)-N-tert-butyl- dimethylsilyloxy-N -(α-methylbenzyl)amide. The isoxazolidin-5-ones are then globally de- protected via hydrogenolysis, giving rise to the corresponding β2,2,3-amino acids.
Chapter 4 focuses on the development of a protocol to effect the conjugate addition of a chiral aniline equivalent. The scope of the reaction is delineated by varying both the nu- cleophile and the α,β-unsaturated ester. Finally, cyclisation of the β-N-arylamino esters to the corresponding tetrahydroquinolines is explored, and an application to the synthesis of the natural product (−)-angustureine is presented.
Chapter 5 contains full experimental procedures and characterisation data for all com- pounds synthesised in Chapters 2, 3 and 4.
|Digital Origin:||Born digital|
|Type of Award:||DPhil|
|Level of Award:||Doctoral|
|Awarding Institution:||University of Oxford|
|Copyright Holder:||Scott Bentley|