Reaction with difluoromethyl radical

Difluoromethyl radicals were produced by photo-initiated Se-CF2 bond cleavage of ethyl a,a-difluoro-a-(phenylseleno)acetate. Their reaction with thiophene gave the product of 2-difluoromethylation (Scheme 145) [209]. 

Another type of reactivity was disclosed for difluorochloro group in pyrimidine series. Recently Iaroshenko, Langer and co-workers shown that difluorochloro substituted pyrimidines 1227 can be converted into corresponding difluoromethyl pyrimidines 1228 by radical reduction with tributyltin hydride in the presence of AIBN in moderate yields. In addition, CFaCl-substituted pyrimidines 1227 were transformed to the corresponding l,l-difluorobut-3-enyl pyrimidines 1129 by reaction with aUyltributyltin and AIBN. In this case the yields of transformation are lower in comparison with tributyltin hydride reduction (Schane 269) [412]. 

---