COMMUNICATIONS
Experimental Section
trans-[RuCl2(phosphane)2(1,2-diamine)] and
Chiral trans-[RuCl2(diphosphane)(1,2-dia-
mine): Shelf-Stable Precatalysts for the Rapid,
Productive, and Stereoselective Hydrogenation
of Ketones**
Typical procedure for an iodine ± magnesium exchange reaction: Prepara-
tion of 3l: A solution of ethyl 4-iodobenzoate (552 mg, 2 mmol) in THF
(20 mL) was cooled to 408C, and iPr2Mg (2.3 mL, 1.06 mmol) in tert-butyl
methyl ether was added. After 1 h at 408C, benzaldehyde (233 mg,
2.2 mmol) was added. After stirring for 3 h, the reaction mixture was
worked up as usual to give a crude yellow oil, which was purified by flash
chromatography (pentane/ether, 80/20) to give 460 mg of pure 3l (90%
yield).
Henri Doucet, Takeshi Ohkuma, Kunihiko Murata,
Tohru Yokozawa, Masami Kozawa, Eiji Katayama,
Anthony F. England, Takao Ikariya, and Ryoji Noyori*
Typical procedure for an iodine ± magnesium exchange reaction on the
solid phase: Preparation of 5a: Wang resin (100 mg) charged with 4-
iodobenzoic acid (70 mmol) was dried for 2 h under vacuum (0.1 Torr) at
508C. After cooling to room temperature under an inert atmosphere, the
resin was allowed to swell for 10 min in THF (2 mL). The heterogeneous
mixture was cooled to 358C, and a solution of iPrMgBr (0.70 mL,
0.51 mmol, 0.73m) in THF was added. After stirring for 15 min, a solution
of CuCN ´ 2LiCl (0.70 mL, 0.7 mmol, 1.0m) was added, followed, after a
further 15 min, by allyl bromide (0.30 mL, 50 equiv). After stirring for
40 min, the reaction mixture was filtered, and the resin was successively
washed with DMF, MeOH, and CH2Cl2 (six cycles) and treated with
CF3CO2H (4 mL of CF3CO2H/CH2Cl2/H2O, 9/1/1) for 20 min. After
filtration and evaporation of the volatile materials under high vacuum,
5a (10.8 mg, 95% yield) was isolated as a white solid. The HPLC purity was
98% (RP-18, MeCN/H2O, 0.1% CF3CO2H; UV detection at 254 nm).
We recently discovered that a system comprising [RuCl2-
(phosphane)n], 1,2-diamine, and an inorganic base is an
excellent catalyst for the hydrogenation of simple ketones in
2-propanol, at high substrate/catalyst molar ratios (S/C) under
mild conditions.[1] In addition to other features, this reaction is
characterized by high diastereo-, enantio-, and C O/C C
selectivity. However, the concentration of the catalytic species
generated in situ remains unknown. Because the quantities of
the metallic and organic components used are extremely
small, it is possible that the intermolecular reactions may be
incomplete. Furthermore, the catalytically active metal com-
plexes may not be the only complexes formed. We speculated
that the use of a pure, stable phosphane/diamine complex
would significantly increase the catalytic efficiency. We
describe here procedures for the preparation of RuII com-
plexes with phosphane and diamine ligands from commercial
or other readily available materials. As expected, these
complexes proved to be exceedingly efficient hydrogenation
precatalysts. The reaction rate and productivity were two
orders of magnitude higher than those obtained from the
complexes generated in situ.
Received: January 26, 1997 [Z11403IE]
German version: Angew. Chem. 1998, 110, 1801 ± 1804
Keywords: copper ´ Grignard reactions ´ iodine ± magnesi-
um exchange ´ magnesium ´ solid-phase synthesis
[1] Handbook of Grignard-Reagents (Eds.: G. S. Silverman, P. E. Rakita),
Marcel Dekker, New York, 1996.
[2] G. H. Posner, Org. React. 1975, 22, 253; B. H. Lipshutz, S. Sengupta,
ibid. 1992, 41, 135; T.-Y. Luh, Acc. Chem. Res. 1991, 24, 257; K. Tamao,
K. Sumitani, M. Kumada, J. Am. Chem. Soc. 1972, 94, 4374; R. J. P.
Corriu, J. P. Masse, J. Chem. Soc. Chem. Commun. 1972, 144; T.
Hayashi, M. Kumada, Acc. Chem. Res. 1982, 15, 395; E. Negishi, A. O.
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12; Angew. Chem. Int. Ed. Engl. 1983, 22, 31; M. T. Reetz, Angew.
Chem. 1984, 96, 542; Angew. Chem. Int. Ed. Engl. 1984, 23, 556; G.
Cahiez, S. Marquais, M. Alami, Org. Synth. 1993, 72, 135; G. Cahiez, B.
Laboue, Tetrahedron Lett. 1992, 33, 4439.
Achiral Ru type 1 complexes with triarylphosphane, ethyl-
enediamine, and chloro ligands were prepared by the addition
of two equivalents of ethylenediamine to [RuCl2(phos-
phane)3][2] in CH2Cl2 at 258C. The mixture was stirred for
three hours (method A). Type 2 chiral complexes were most
Cl
Cl
H2
N
R1
H2
N
Ar2
P
Â
[3] Examples of halogen ± magnesium exchange reactions: J. Villieras,
R2
R3
Ar3P
Ar3P
Bull. Soc. Chim. Fr. 1967, 1520; H. H. Paradies, H. Görbing, Angew.
Chem. 1969, 81, 293; Angew. Chem. Int. Ed. Engl. 1969, 8, 279. C. F.
Smith, G. J. Moore, C. Tamborski, J. Organomet. Chem. 1971, 33, C21;
G. Cahiez, D. Bernard, J. F. Normant, ibid. 1976, 113, 107; D. Seyferth,
R. Lambert, ibid. 1973, 54, 123; N. Redwane, P. Moreau, A.
Commeyras, J. Fluorine Chem. 1982, 20, 699; N. Furukawa, T.
Shibutani, H. Fujihara, Tetrahedron Lett. 1987, 28, 5845; H. Nishiyama,
K. Isaka, K. Itoh, K. Ohm, H. Nagase, K. Matsumoto, H. Yoshiwara, J.
Org. Chem. 1992, 57, 407; C. Bolm, D. Pupowicz, Tetrahedron Lett. 1997,
38, 7349.
Ru
Ru
N
H2
P
Ar2
N
H2
Cl
1
Cl
2
[*] Prof. R. Noyori,[] Dr. H. Doucet, Prof. T. Ohkuma[]
Department of Chemistry and Molecular Chirality Research Unit
Nagoya University
[4] P. Knochel, M. C. P. Yeh, S. C. Berk, J. Talbert, J. Org. Chem. 1988, 53,
2390.
[5] F. Balkenhohl, C. vom dem Bussche-Hünnefeld, A. Lansky, C. Zechel,
Angew. Chem. 1996, 108, 2436; Angew. Chem. Int. Ed. Engl. 1996, 35,
2288; J. S. Früchtel, G. Jung, Angew. Chem. 1996, 108, 19; Angew.
Chem. Int. Ed. Engl. 1996, 35, 17.
[6] Supplied by Bachem Bioscience Inc., King of Prussia, PA, USA.
[7] I. Klement, K. Lennick, C. E. Tucker, P. Knochel, Tetrahedron Lett.
1993, 34, 4623.
[8] A patent covering the preparation of polyfunctional Grignard reagents
has been submitted.
Chikusa, Nagoya 464-8602 (Japan)
Fax: (81)52-783-4177
K. Murata, T. Yokozawa, M. Kozawa, E. Katayama,
Dr. A. F. England, Prof. T. Ikariya[]
ERATO Molecular Catalysis Project
Japan Science and Technology Corporation
1247 Yachigusa, Yakusa-cho, Toyota 470-0392 (Japan)
[ ] Professors Noyori and Ohkuma were also members of the ERATO
Project.
[
] Present address:
Department of Chemical Engineering, Faculty of Engineering
Tokyo Institute of Technology, Meguro, Tokyo 152-8552 (Japan)
[**] This work was supported by the Ministry of Education, Science,
Sports, and Culture of Japan (No. 07CE2004).
Angew. Chem. Int. Ed. 1998, 37, No. 12
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1998
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