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Efficient Synthesis and Analysis of Chiral Cyanohydrins

This thesis deals with the development of new methods for efficient synthesis and analysis in asymmetric catalysis. It focuses on the preparation of chiral cyanohydrins by enantioselective addition of cyanide to prochiral aldehydes. The initial part of the thesis describes the development of a dual Lewis acid– Lewis base activation system for efficient synthesis of chiral O-acylated and Ocarbonylated cyanohydrins. This system was used for the preparation of a variety of cyanohydrins in high isolated yields and with up to 96% ee. Activation of the cyanide by nucleophilic attack of the Lewis base at the carbonyl carbon atom was supported experimentally. Secondly, convenient procedures for the synthesis of polymer-bound chiral YbCl3-pybox and Ti-salen complexes are described. The polymeric complexes were employed in cyanation of benzaldehyde. A T-shaped microreactor was used for screening of reaction conditions for the enantioselective cyanation of benzaldehyde using trimethylsilyl cyanide and acetyl cyanide as cyanide sources. A microreactor charged with the polymeric Tisalen complex was used for enantioselective cyanation of benzaldehyde. Finally, an enzymatic method for high throughput analysis of ee and conversion of products from chiral Lewis acid–Lewis base-catalysed additions of α- ketonitriles to prochiral aldehydes was developed. The method could be used for the analysis of a variety of O-acylated cyanohydrins. Microreactor technology was successfully combined with high throughput analysis for efficient catalyst optimisation. / QC 20100809

Identiferoai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kth-4315
Date January 2007
CreatorsLundgren, Stina
PublisherKTH, Kemi, Stockholm : KTH
Source SetsDiVA Archive at Upsalla University
LanguageEnglish
Detected LanguageEnglish
TypeDoctoral thesis, comprehensive summary, info:eu-repo/semantics/doctoralThesis, text
Formatapplication/pdf
Rightsinfo:eu-repo/semantics/openAccess
RelationTrita-CHE-Report, 1654-1081 ; 2007:11

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