Marie Kissane

ReactNMR and ReactIR as reaction monitoring and mechanistic elucidation tools: the NCS mediated cascade reaction of α-thioamides to α-thio-β-chloroacrylamides.

On-flow ReactIR and (1)H NMR reaction monitoring, coupled with in situ intermediate characterization, was used to aid in the mechanistic elucidation of the N-chlorosuccinimide mediated transformation of an α-thioamide. Multiple intermediates in this reaction cascade are identified and characterized, and in particular, spectroscopic evidence for the intermediacy of the chlorosulfonium ion in the chlorination of α-thioamides is provided. Further to this, solvent effects on the outcome of the transformation are discussed. This work also demonstrates the utility of using a combination of ReactIR and flow NMR reaction monitoring (ReactNMR) for characterizing complex multicomponent reaction mixtures.

Investigation of the synthetic and mechanistic aspects of the highly stereoselective transformation of α-thioamides to α-thio-β-chloroacrylamides

Treatment of a series of α-thioamides with N-chlorosuccinimide results in efficient transformation to the analogous α-thio-β-chloroacrylamides. The mechanistic pathway has been established through isolation and characterisation of intermediate compounds. The scope of the transformation has been explored—aryl and alkylthio substituents, primary, secondary and tertiary amides can be employed. In most instances, the chloroacrylamides are formed exclusively as the Z-stereoisomer; however, with tertiary propanamides or with amides derived from butanoic or pentanoic acid a mixture of E- and Z-stereoisomers is formed.