Applications of isothioureas in surface chemistry : modification of self-assembled monolayers and immobilisation on polymer supports

Monomolecular films;Surface chemistry;Thiourea

Chisholm, Ross ; Smith, Andrew David ; Smith, Andrew David

University:University of St Andrews

Department:Chemistry (School of)

关键词: Monomolecular films;    Surface chemistry;    Thiourea;   

Others  :  https://research-repository.st-andrews.ac.uk/bitstream/handle/10023/16925/RossChisholmPhDThesis.pdf?sequence=2&isAllowed=y

来源: DR-NTU

【 摘 要 】

The research outlined in this thesis describes the development of organocatalytic methodologyfor the modification of self-assembled monolayers on silicon dioxide surfaces and its extensiontowards an asymmetric protocol and immobilisation of isothiourea organocatalysts to polystyrenesupports.Chapter 1 aims to describe the fundamental aspects of self-assembled monolayers and their placewithin the wider area of surface chemistry. A recent overview of catalytic surfacefunctionalisation is discussed as well as the historical context of this project, with respect toresearch within the Smith group, is also presented. A statement of the initial aims and objectivesof the research is presented.Chapter 2 describes the proof-of-concept study undertaken to develop methodology towards thefunctionalisation of silicon oxide surfaces using an isothiourea-catalysed organocatalytic Michaeladdition-lactonisation process. Subsequent characterisation of the resulting surfaces and areaction scope is also carried out in this system.Chapter 3 describes an extension of the methodology carried out in the previous chapter to allowfor an asymmetric protocol. The sense of enantioenduction of the resulting surfaces was thenexamined using chemical force microscopy using a novel AFM probe with the results show thatchiral discrimination can be achieved using this methodology. Control experiments were alsoundertaken by depositing enantiopure starting materials on a surface and measuring the adhesionforces confirming the presence of a chiral surface.Chapter 4 describes the immobilisation (R)-BTM and (2R,3S)-HyperBTM analogues ontopolystyrene supports and their evaluation in several different reaction classes previouslyinvestigated within the Smith group. Results show that the polymer-supported catalyst (2R,3S)-HyperBTM can be recycled up to 8 times without any major loss in yield or selectivity.Chapter 5 offers a brief summary of the work undertaken in this PhD and some of the conclusionsthat can be drawn from it as well as an insight into the potential future developments of thisresearch and areas where it could possibly expand and develop.