Abstract
Ferrocenyl-1,2-diketones FcCOCOR,
3, [Fc = (C
5H
5)Fe(C
5H
4)] can be prepared by oxidation of acylferrocenes FcCOCH
2R or, more efficiently, by oxidation of the isomeric ketones FcCH
2COR,
2. The ketones
2 are in turn readily synthesized from the salt (FcCH
2PPh
3)
+I
− via the acylated salts [FcCH(COR)PPh
3]
+I
−. The haloacylferocenes FcCOCCl
x
H
3−
x
(
x = 1, 2, 3, of which the
x = 2 example is synthetically equivalent to a diketone) are synthesized by Friedel—Crafts acylation of ferrocene using CCl
x
H
3−
x
COCl/AlCl
3, but the reaction proceeds via two parallel pathways, one giving the normal acyl derivatives FcCOCCl
x
H
3−
x
and the other giving the reduced products FcCOCCl
x−1
H
4−
x
. Two diketones FcCOCOFc
3b and FcCOCOC
6H
4Ph
3c have been structurally characterised by single-crystal X-ray diffraction.