Synthesis and Comparison of the Reactivity of Allyl Fluorides and ...

3.3 Conclusions
93
Chapter Three
The novel Pd(II) chloride-bridged dimers (125), (126), (127), (128), (129), (130) and (131)
have been synthesised from their corresponding allylic chlorides and purified by column
chromatography. Their structures were determined by NMR spectroscopy, mass
spectrometry and X-ray crystallography. The novel cationic complexes (132), (134) and
(135) have also been synthesised but not isolated in the reactions of (74), (75) and (108)
with Pd(dba)2 and PPh3 in CDCl3. Their structures were determined by NMR spectroscopy
and mass spectrometry. It was observed that the allylic chloride (108) and allylic fluoride
(75) both oxidatively add to Pd(0) in the same manner. However, with (74) though the
cationic species was formed, due to the electron-withdrawing property of the phthalimido
group, the protons alpha to nitrogen are susceptible to elimination by fluoride which acts as
a base to form 2-(buta-1,3-dienyl)isoindoline-1,3-dione (133). In the next chapter only the
cationic species (135) synthesised from (108) will be reacted further with nucleophiles,
though both (108) and (75) form the same product, it is easier to synthesise the allylic
chloride precursor rather than the allylic fluoride.
(125) R= H
(126) R= H
(127) R= 4-F
(128) R= 3-F
(129) R= 2-F
(130) R= CF3
(131) R= CH3
R’= C=O
R’= CH2
R’= C=O
R’= C=O
R’= C=O
R’= C=O
R’= C=O
(134) X= F
(135) X= Cl
Figure 3.11 Novel compounds synthesised (125) – (135)