Lead Tetraacetate Induced Addition Reaction of Difluorodiiodomethane to Alkenes and Alkynes. Synthesis of Fluorinated Telechelic Compounds
作者:An-Rong Li、Qing-Yun Chen
DOI:10.1055/s-1997-1378
日期:1997.12
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.
Polyfluorodiacyl fluorides having the formula FOC(CFXOCF.sub.2).sub.p (CF.sub.2).sub.n-1 (CF.sub.2 OCFX).sub.q COF wherein n represents an integer of 2 to 4; X represents fluorine or chlorine atom or trifluoromethyl group; p=0 to 5; q=0 to 5; p+q>1 are produced by reacting a perfluorolactone with a fluorocarbon epoxide, optionally in the presence of an aprotic polar solvent and a nucleophilic reagent.