Lead Tetraacetate Induced Addition Reaction of Difluorodiiodomethane to Alkenes and Alkynes. Synthesis of Fluorinated Telechelic Compounds

Abstract

Lead tetraacetate (LTA) can smoothly induce the addition reaction of difluorodiiodomethane (1) with electron-rich alkenes at 60°C in diglyme to give monoadducts (RCHICH₂CF₂I) and diadducts (RCHICH₂)₂. The similar, clean reaction of fluoroolefins, such as tetrafluoroethene, hexafluoropropene, with 1 occurs only in acetic acid. However, non-fluorinated β-iodo-α,β-unsaturated carboxylic esters are obtained when 1 reacts with alkynes in alcohol. The iododifluoromethyl radical generated by possible pathways from 1 with LTA is discussed.