‡ Characteristic analytical data for 5c: dH(C6D6, 300 MHz) 211.8 (br),
dP(C6D6, 121 MHz) 67.9. nmax(KBr)/cm21 2105, 1990, 1552. Found: C,
59.43; H, 9.72; P, 13.03. Calc. for C54H106P4Ru2: C, 59.97; H, 9.88; P,
11.46%. 5b: dH(C6D6, 300 MHz) –11.2, dP(C6D6, 121 MHz) 114.3.
§ We note that the conversion of acetophenone varied between 50 and 100%
in several independent catalytic runs. The reason for this is as yet unclear
and is part of our current investigations.
largely unreactive and gave low, but clean conversion to 5b
( < 30%).‡ 31P-NMR monitoring of the reaction of 4a with H2
indicated also a very slow reaction. Two different phosphorus
containing products were formed, but there were no unambigu-
ously detectable signals in the hydride region of the H NMR
spectrum.
1
Preliminary results of some Murai-type couplings using 1 as
catalyst precursor are summarised in Table 2. In agreement with
Chaudret’s recent findings, the alkylation of acetophenone with
one molecule of ethylene proceeded smoothly in presence of 1
(10 mol%) under mild conditions.6§ Appreciable amounts of
the dialkylated product were formed at 50 °C. Most notably,
coupling of 2-a-styrylpyridine and ethylene occurred readily to
give a mixture of mono- and di-alkylated products at 30 °C. This
coupling has been previously reported only for rhodium
catalysts under much more forcing conditions.12
Further evaluation of the new procedure for the synthesis of
ruthenium hydrides and detailed investigation of their catalytic
behaviour are under way.
Financial support by the Max-Planck-Society and the
Deutsche Forschungsgesellschaft is gratefully acknowledged.
We thank Dr Tom Baker (Los Alamos National Laboratory) for
helpful discussion.
1 B. Chaudret and R. Poilblanc, Organometallics, 1985, 4, 1722.
2 (a) T. Arliguie, B. Chaudret, R. H. Morris and A. Sella, Inorg. Chem.,
1988, 27, 598; (b) B. Chaudret, J. Devillers and R. Poilblanc,
Organometallics, 1985, 4, 1727.
3 G. J. Kubas, Acc. Chem. Res., 1988, 21, 120.
4 A. F. Borowski, S. Sabo-Etienne, M. L. Christ, B. Donnadieu and B.
Chaudret, Organometallics, 1996, 15, 1427.
5 T. R. Belderain and R. H. Grubbs, Organometallics, 1997, 16, 4001.
6 Y. Guari, S. Sabo-Etienne and B. Chaudret, J. Am. Chem. Soc., 1998,
120, 4228.
7 M. Sonoda, F. Kakiuchi, N. Chatani and S. Murai, Bull. Chem. Soc. Jpn.,
1997, 70, 3117.
8 K. Itoh, H. Nagashima, T. Ohshima, N. Oshima and H. Nishiyama,
J. Organomet. Chem., 1984, 272, 179.
9 R. P. Beatty and R. A. Paciello (Du Pont), WO 96/23804, priority date
08/08/1996.
10 W. Leitner, M. Bühl, R. Fornika, C. Six, W. Baumann, E. Dinjus, M.
Kaiser, C. Krüger and A. Rufin´ska, Organometallics, 1999, 18, 1196
and references therein.
11 W. Leitner and C. Six, Chem. Ber./Recueil, 1997, 130, 555; C. Six, B.
Gabor, H. Görls, R. Mynott, P. Philipps and W. Leitner, Organome-
tallics, 1999, 18, 3316.
12 Y.-G. Lim, J.-B. Kang and Y. H. Kim, J. Chem. Soc., Perkin Trans. 1,
1998, 699.
Notes and references
3
† [Ru(cod)(h -C4H7)2] was purchased from Fisher Scientific/ACROS
Organics and used as received. For synthesis from [Ru(cod)Cl2]n, see K. S.
MacFarlane, S. J. Rettig, Z. Liu and B. R. James, J. Organomet. Chem.,
1998, 557, 213.
Communication 9/06580F
2306
Chem. Commun., 1999, 2305–2306