S-Succinimidomethyl- and S-phthalimidomethyl xanthates are added efficiently to various alkenes resulting in an overall aminomethylation process. In contrast, under similar conditions, S-pyrrolidonyl xanthate gives rise mostly to oligomers. This unexpected difference in reactivity is attributed to the more important allylic character of the intermediate radical in the case of the imide derivative as compared to the lactam.