Enantiocontrolled synthesis of polychlorinated hydrocarbon motifs: A nucleophilic multiple chlorination process revisited

Polychlorinated hydrocarbon motifs have been synthesized in enantiomerically pure forms by means of nucleophilic multiple chlorinations of chiral epoxides, which stereospecifically incorporate halogen atoms into oxygenated molecular scaffolds. The present study demonstrates the scope of the N-chlorosuccinimide (NCS)/organophosphine reagent system that forms multiple sp³C-Cl bonds in a regularly repeating pattern with proper stereochemical configurations and evaluates its applicability to various epoxides having elaborate structures. It is noteworthy that tetrachlorinated motifs are produced in one step from bisepoxides by using NCS/Ph3P. Furthermore, Ph2PCl used in combination with NCS has been found to serve as a potentially useful alternative to NCS/Ph3P, especially for promoting dichlorination reactions of alkenyl-substituted epoxides.