Perfluoroalkyl-Substituted Thiophenes and Pyrroles from Donor–Acceptor Cyclopropanes and Heterocumulenes: Synthesis and Exploration of their Reactivity
作者:Daniel Gladow、Hans-Ulrich Reissig
DOI:10.1021/jo500534t
日期:2014.5.16
A methyl 2-trifluoromethyl-2-siloxycyclopropanecarboxylate was smoothly deprotonated by lithium diisopropylamide and reacted with carbon disulfide and methyl iodide to afford a dihydrothiophene derivative. The crucial step in this transformation is a ring-expansion of the anionic intermediate by [1,3] sigmatropic rearrangement. The dihydrothiophene was converted into the corresponding 5-trifluoromethylthiophene