Continuous Flow Organocatalytic Chlorination of Alkenes

A regioselective anti‐dichlorination and allylic chlorination of isolated double bonds is described. Such chlorination reactions benefit from a combination of methyl phenyl sulfoxide and TMSCl. The method has been appropriately adjusted to fit the continuous flow technology requirements, aiming to a broader industrial implementation for the synthesis of pharmaceutically important compounds. Towards the same direction, a catalytic protocol has been developed, using sub‐stoichiometric amount of sulfoxide and environmentally friendly H2O2 as the stoichiometric oxidant, with comparable efficacy. A continuous flow‐friendly organocatalytic chlorination of alkenes has been developed. The method implicates the catalytic system PhS(O)Me/TMSCl and makes use of environmentally benign H2O2, as the stoichiometric regenerator of the sulfoxide catalyst. Under these conditions, internal disubstituted and terminal alkenes cleanly convert to the corresponding anti‐dichlorides, while electron rich trisubstituted or 1,1‐disubstituted alkenes provided allylic chlorination products.