|Title:||ReactNMR and ReactIR as Reaction Monitoring and Mechanistic Elucidation Tools: The NCS Mediated Cascade Reaction of α-Thioamides to α-Thio-β-chloroacrylamides|
|Authors:||David A. Foley, Christopher W. Doecke, Jonas Y. Buser, Jeremy M. Merritt, Linda Murphy, Marie Kissane, Stuart G. Collins, Anita R. Maguire, and Andreas Kaerner|
|Reference:||J. Org. Chem., 2011, 76 (23), pp 9630–9640|
On-flow ReactIR and 1H 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.