Page 793 - Advanced Organic Chemistry Part B - Reactions & Synthesis

Scheme 8.17. Reactions of Cyclobutadiene 769

SECTION 8.5
Fe Organometallic
C C Compounds with
O C O -Bonding
O
Ce(IV) or
OC H Ph(OAc)
C O
H 5 2 2 5 4
H
OC 2 5
OC H
2 5
(Ref. a)
O (Ref. c)
2
2
CH 3 O CCH CHCO CH 3
O
O
CO CH 3
2
(Ref. b) CO 2 CH 3 (Ref. d)
O
a. J. C. Barborak and R. Pettit, J. Am. Chem. Soc., 89, 3080 (1967).
b. J. C. Barborak, L. Watts, and R. Pettit, J. Am. Chem. Soc., 88, 1328 (1966).
c. L. Watts, J. D. Fitzpatrick, and R. Pettit, J. Am. Chem. Soc., 88, 623 (1966).
d. P. Reeves, J. Henery, and R. Pettit, J. Am. Chem. Soc., 91, 3889 (1969).

Many other -organometallic compounds have been prepared. In the most stable
of these, the total number of electrons contributed by the ligands (e.g., four for allyl
anions and six for cyclopentadiene anion) plus the valence electrons on the metal atom
or ion is usually 18, to satisfy the effective atomic number rule. 318

O
C
Mn Ni Ti
C C C
O C O N O
O O
Metal 6 9 2
Ligands 12 9 16
Total 18 18 18
One of the most useful types of complexes of aromatic compounds from
the synthetic point of view are chromium tricarbonyl complexes obtained by heating
benzene or other aromatics with Cr CO .
6

+ Cr(CO) 6

Cr(CO) 3 Ref. 319
318 M. Tsutsui, M. N. Levy, A. Nakamura, M. Ichikawa, and K. Mori, Introduction to Metal -Complex
Chemistry, Plenum Press, New York, 1970, pp. 44–45; J. P. Collman, L. S. Hegedus, J. R. Norton,
and R. G. Finke, Principles and Applications of Organotransition Metal Chemistry, University Science
Books, Mill Valley, CA, 1987, pp. 166–173.
319
W. Strohmeier, Chem. Ber., 94, 2490 (1961).