Catalytic C–F bond activation of geminal difluorocyclopropanes by nickel(<scp>i</scp>) complexes via a radical mechanism
作者:Jan Wenz、Christoph A. Rettenmeier、Hubert Wadepohl、Lutz H. Gade
DOI:10.1039/c5cc08950f
日期:——
Nickel(II) fluorido complexes bearing NNN-pincer ligands were found to be catalysts in the hydrodefluorination of geminal difluorocyclopropanes which undergo ring-opening to form the corresponding monofluoroalkenes in good yield and high Z-selectivities.
There is described a process for the preparation of compounds of formula I
in which
R is hydrogen, optionally substituted alkyl, optionally substituted alkenyl optionally substituted cycloalkyl, optionally substituted phenyl or optionally substituted heterocyclyl, and
R1 and R2 are hydrogen, an organic radical or together with the ring to which they are attached, form an optionally substituted ring, which may contain one or more hetero atoms,
which comprises reacting a compound of formula II
with a compound of formula III
in which the ring Q is an optionally substituted heteroaromatic ring, which optionally comprises one or more further hetero atoms and to which is optionally fused an optionally substituted ring.
Transition metal free decarboxylative fluorination of cinnamic acids with selectfluor®
作者:Cheng-Tan Li、Xi Yuan、Zhen-Yu Tang
DOI:10.1016/j.tetlet.2016.11.003
日期:2016.12
Herein we report a transition metal free decarboxylative fluorination of cinnamic acids with selectfluor®. A range of functionalized cinnamic acid derivatives reacted with 2 equiv. of selectfluor® and 4 equiv. of base in hydrophobic solvent and water to afford β-fluorostyrene with good yield and Z-stereoselectivity. Kinetic study was conducted.
Alkenyl(phenyl)iodonium tetrafluoroborates dissolved in chloroform, or in the solid state, decompose thermally at 60 degrees C to yield fluoroalkenes and iodobenzene as major products via an S(N)1- or S(N)2-type reaction within the ion pair of the substrates. (C) 2000 Elsevier Science Ltd. All rights reserved.