A series of bifunctionalized styrene molecules have been prepared by dithiocarbamylation of alkynyl bromides under catalyst and additive free condition. Freshly prepared dithiocarbamic acid reacts with alkynyl bromide under metal‐free condition following a concerted process to produce alkynyl‐dithiocarbamate intermediate as revealed from computational studies of the mechanism. Concerted nucleophilic substitution at C(sp)‐center occurs through a 3‐atom centered transition state. Neighboring‐group‐assisted addition of dithiocarbamic acid to the alkynyl‐dithiocarbamate intermediate furnishes stereoselectively Z ‐styrenyl‐1,2‐bis dithiocarbamate compounds. The protocol is tested on gram‐scale synthesis and explored on substrates containing bioactive moieties.
Mondal et al. (Fri,) studied this question.