(E)-1,2-Difluoro-1-iodo-2-trialkylsilanes—A useful synthon for the addition of the [IFCCF] unit to activated electrophiles

Fluoride ion catalyzed reaction of (E)-IFCCFSiR₃ with activated aromatic aldehydes and ketones and activated perfluoroaromatics, such as pentafluoropyridine and perfluorotoluenes, transfers the IFCCF] unit to the activated electrophiles to stereospecifically provide (E)-1,2-difluoro-1-iodosubstituted derivatives. Aluminum chloride catalyzed reaction of (E)-1,2-difluoro-1-iodo-2-trialkylsilanes with alkyl or aryl acyl halides gives the corresponding (E)-1,2-difluoro-1-iodoketones stereospecifically in excellent yield. The vinyl iodide product formed via this methodology could be coupled (with Pd(0)) catalysis to provide an entry to a polyfunctionalized derivative.