58
U. Schubert et al. / Journal of Organometallic Chemistry 646 (2002) 53–58
(
b) P. Braunstein, F. Naud, Angew. Chem. 113 (2001) 702;
lanes can be promoted by employing hemilabile chelat-
ing ligands. The reactivity of the complexes can be
somewhat varied by modifying the properties of the
P,N-chelating ligand (kind and length of spacer group
between P and N; substituents at N).
Angew. Chem. Int. Ed. Engl. 40 (2001) 680;
(
c) A. Bader, E. Lindner, Coord. Chem. Rev. 108 (1991) 27.
[
2] H.A. Ankersmit, B.H. Løken, H. Kooijman, A.L. Spek, K.
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The calculated enthalpies for the reaction of SiH4
2
with [(k -P,N)ꢀH PCH CH NH ]PtMe (DE= −111.2
2
2
2
2
2
−
1
−1
kJ mol ) or (H P) PtMe (DE= −103.3 kJ mol ) to
3
2
2
[
5] J. Pfeiffer, G. Kickelbick, U. Schubert, Organometallics 19
2000) 62.
[6] F. St o¨ hr, U. Schubert, unpublished results.
the corresponding methyl(silyl) complexes are very sim-
(
ilar [9] (it can be assumed that the reaction enthalpy for
2
[
[
7] J. Pfeiffer, U. Schubert, Organometallics 18 (1999) 3245.
8] J. Pfeiffer, F. St o¨ hr, S. Thompson, U. Schubert, unpublished
results.
9] D. Sturmayr, G. Kickelbick, U. Schubert, unpublished results.
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[11] M. Okazaki, H. Tobito, H. Ogino, J. Chem. Soc. Dalton Trans.
[
(k -P,P)ꢀH PCH CH PH ]PtMe is of the same magni-
2
2
2
2
2
tude). Nevertheless, no reactions were observed be-
tween (dppe) PtMe complexes and silanes, while the
2
2
[
corresponding (PSN)PtMe complexes react rapidly.
2
This implies that the latter reaction is driven by the
easier cleavage of the PtꢀN bond.
(
1997) 3531.
[
[
12] J.Y. Corey, J. Braddock-Wilking, Chem. Rev. 99 (1999) 175.
13] (a) L.S. Chang, M.P. Johnson, M. Fink, Organometallics 10
The redistribution reactions mentioned above indi-
cate that the opening of a coordination site not only
promotes oxidative addition and possibly s-bond
metathesis reactions, but—different to carbon com-
pounds—also induces migrations of silicon substituents
with the concomitant formation of silylene complex
intermediates. It was pointed out by Tilley et al. that
the transfer of a silyl substituent from silicon to plat-
inum is easier in three- than in four-coordinated com-
plexes [19]. The formation of the three-coordinate com-
plex is of course easier with a PSN ligand than with
(
(
1991) 1219;
b) D.C. Pestana, T.S. Koloski, D.H. Berry, Organometallics 13
(1994) 4173;
(
(
(
(
(
c) L.K. Figge, P.J. Carroll, D.H. Berry, Organometallics 15
1996) 209;
d) H. Yamashita, M. Tanaka, M. Goto, Organometallics 11
1992) 3227;
e) M.D. Curtis, P.S. Epstein, Adv. Organomet. Chem. 19 (1981)
213.
[
14] For example: (a) K. Ueno, H. Tobita, M. Shimoi, H. Ogino, J.
Am. Chem. Soc. 110 (1988) 4092;
(
b) H. Tobita, K. Ueno, M. Shimoi, H. Ogino, J. Am. Chem.
two PR or a bisphosphine ligand.
3
Soc. 112 (1990) 3415;
(
(
c) K. Ueno, H. Ogino, Bull. Chem. Soc. Jpn. 68 (1995) 1955;
d) K. Ueno, A. Masuko, H. Ogino, Organometallics 18 (1999)
2
694.
15] J. Pfeiffer, G. Kickelbick, U. Schubert, Organometallics 19
2000) 957.
Acknowledgements
[
[
(
We thank the Fonds zur F o¨ rderung der Wis-
senschaftlichen Forschung (FWF), Vienna, for the sup-
port of our work.
16] F. St o¨ hr, D. Sturmayr, G. Kickelbick, U. Schubert,
Organometallics, submitted for publication.
[17] F. St o¨ hr, U. Schubert, J. Chem. Soc. Chem. Commun., submit-
ted for publication.
[
[
18] G.P.C.M. Dekker, A. Buijs, C.J. Elsevier, K. Vrieze,
Organometallics 11 (1992) 1937.
19] (a) J.D. Feldman, G.P. Mitchell, J.-O. Nolte, T.D. Tilley, J. Am.
Chem. Soc. 120 (1998) 11184;
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