Preparation of fluoroalkenes from fluoroacetonitrile

α-Fluoroacrylonitriles: Horner–Wittig synthesis and conversion into 2-fluoroallylamines and C-(1-fluorovinyl)nitrones

“…Reaction of fluoroacetonitrile with diethyl chlorophosphate in the presence of 2 eq. of base, followed by addition of aromatic aldehydes, yielded afluorocinnamonitrile derivatives with little stereoselectivity [8]. The likely intermediary phosphonate could not be identified [8].…”

“…On the one hand, the electronpoor double bond provides the possibility of applying both the Michael addition [4], and the Diels-Alder reaction [5]. On the other hand, the nitrile function can be converted into an ester through the Pinner reaction [6], or into an aldehyde by reduction with diisobutylaluminum hydride (DIBALH) and hydrolysis [7,8]. The resulting aldehydes were converted into mono-fluorinated dienes by Wittig reactions.…”

“…The most general route is based on the Horner-Wadsworth-Emmons (HWE) reaction of a cyanofluoromethyl-substituted phosphonate with carbonyl compounds [7,8,12]. Reaction of fluoroacetonitrile with diethyl chlorophosphate in the presence of 2 eq.…”

“…of base, followed by addition of aromatic aldehydes, yielded afluorocinnamonitrile derivatives with little stereoselectivity [8]. The likely intermediary phosphonate could not be identified [8]. The reaction failed for enolizable aldehydes, possibly caused by an unfortunate choice for the order of addition of the reagents [8].…”

“…The likely intermediary phosphonate could not be identified [8]. The reaction failed for enolizable aldehydes, possibly caused by an unfortunate choice for the order of addition of the reagents [8]. Pure diethyl cyanofluoromethylphosphonate was obtained by electrophilic fluorination of diethyl cyanomethylphosphonate with commercially unavailable N-fluoro[bis(trifluoromethyl)]sulfonimide [12].…”