Z:E-4 was found to be an effective fluoroalkenylation reagent for simple electrophiles. At 25 °C, using TBAF as a catalyst (12 mol%) in THF, the fluoroalkenylation of aldehydes was observed using 1.5 -2.0 equiv. of 4, allowing isolation of products 5a-h (Figure ). The reaction proceeded with good yields for both aliphatic and aromatic substrates, including those with electron-donating and electronwithdrawing groups, ortho-substitution, as well as heteroaromatic substrates. For aromatic aldehydes the reaction produced solely the E-isomer of 5a-g. This is most likely due to the transformation being stereospecific and Z-4 reacting faster than E-4 under the conditions. Consistent with this argument, unreacted E-4 was observed by NMR spectroscopy prior to work-up of crude reactions mixtures. Only in the case of the more reactive aliphatic aldehyde was a mixture of stereoisomeric products 12:1 E/Z-5h observed.