Metal-free visible light-promoted synthesis of isothiazoles: a catalytic approach for N-S bond formation from iminyl radicals under batch and flow conditions

A sustainable synthesis of isothiazoles has been developed using an alpha-amino-oxy acid auxiliary and applying photoredox catalysis. This simple strategy features mild conditions, broad scope and wide functional group tolerance representing a new enviromentally friendly option to prepare these highly valuable heterocycles. Furthermore, the synthetic value of the method is highlighted by the preparation of a natural product derivative and the implementation of the reaction in a continuous flow setup.