Telescoped diazo transfer and rhodium-catalysed S-H insertion in continuous flow

Rhodium-catalysed S-H insertion of alpha-diazo-gamma-butyrolactams has been successfully telescoped using continuous processing with in situ generated triflyl azide in flow and deacylative diazo transfer, incorporating real-time reaction monitoring of the final process outflow by IR spectroscopy. Significantly, the alpha-diazo-gamma-butyrolactam reaction stream was sufficiently pure to progress to the rhodium-catalysed S-H insertion step without detrimental impact on the rhodium catalyst or the reaction efficiency. (C) 2021 The Author(s). Published by Elsevier Ltd.