(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.

Fluoride ion catalyzed reaction of (E)-IFCCFSiR3 with activated aromatic aldehydes and ketones and activated perfluoroaromatics stereospecifically transfers the [IFCCF] unit to directly provide (Z)-1,2-difluoro-1-iodo-substituted derivatives. With AlCl3 catalysis, (E)-ICFCFSiR3 reacts with acyl chlorides to stereospecifically afford (Z)-1,2-difluoro-1-iodo-3-ketones.Figure optionsDownload as PowerPoint slideHighlights
► F− catalyzed addition of (E)-ICFCFSIR3 to activated carbonyl compounds.
► Direct preparation of functionalized fluorinated vinyl iodides.
► Transfer of the [ICFCF] unit to activated electrophiles.
► Pd(0) catalyzed entry to polyfunctionalized fluorine derivatives.