[3,3]-Sigmatropic Rearrangements of Fluorinated Allyl (Thio)cyanates – A Tool for the Synthesis of Fluorinated (Thio)ureas
DOI:
https://doi.org/10.2533/chimia.2014.436Keywords:
Cyanates, 2-fluorallylic alcohols, Fluorinated ureas and thioureas, Isocyanates, Isothiocyanates, [3,3]-sigmatropic rearrangements, ThiocyanatesAbstract
The first (thio)cyanate to iso(thio)cyanate rearrangements based on 2-fluoroallylic alcohols are presented. Long-chain 2-fluoroallylic alcohols were converted to corresponding N-unsubstituted carbamates by treatment with trichloroacetyl isocyanate. Dehydration using trifluoroacetic anhydride in the presence of triethylamine formed intermediate allylic cyanates, which immediately underwent sigmatropic rearrangement to fluorinated allyl isocyanates. Without isolation the latter delivered fluorinated ureas by addition of amines. The thiocyanate to isothiocyanate rearrangements started from the same fluorinated allylic alcohols, which were first converted to mesylates. Heating in THF with potassium thiocyanate led to fluorinated allyl isothiocyanates, via [3,3]-sigmatropic rearrangement of intermediate allyl thiocyanates. The formed products were further reacted with amines to fluorinated thioureas.Downloads
Published
2014-06-26
Issue
Section
Scientific Articles
License
Copyright (c) 2014 Swiss Chemical Society
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
How to Cite
[1]
Chimia 2014, 68, 436, DOI: 10.2533/chimia.2014.436.