3648
N. V. Dubrovina et al. / Tetrahedron: Asymmetry 16 (2005) 3640–3649
4.6. (R,R)-Bis[(di-p-tolyl)phosphino]-1,3-dicyclohexyl-
propane 2b
try and 1964 were observed (I > 2r(I)), R1 = 0.044, wR2
(all data) = 0.112, 254 parameters.
22
D
1
Yield: 0.85 g (31.7%); ½a ¼ ꢀ18:0 (c 0.6, C6H6). H
4.9. [Rh(COD)(2a)]BF4
NMR (C6D6) d 1.13–2.05 (22H, m), 2.21 (d, 12H,
CH3), 2.31 (2H, m), 3.14 (2H, m), 3.65 (2H, m), 6.73–
6.82 (8H, m, arom. H), 7.48–7.54 (8H, m, arom. H);
13C NMR (CDCl3) d 21.4 (CH3, p-Tol), 26.7, 26.9,
27.1, 27.4, 27.7, 28.0, 28.5, 29.7, 31.5, 33.4 (CH2,
C6H11), 33.7 (CH2), 37.9 (CH), 40.5 (CH), 129.7 (arom.
C), 134.3 (arom. C), 135.3 (arom. C), 138.8 (arom. C);
31P NMR (CDCl3) d ꢀ9.3 (s); C43H54P2 (M = 632.84);
MS (70 eV) m/z (%) 618 [MꢀCH3]+ (6), 323 [Mꢀ(p-
Tol)2PCHCy]+ (13), 310 [(p-Tol)2PCHCy]+ (100), 227
[(p-Tol)2PCH2]+ (48), 228 [(p-Tol)2PCH3]+ (73), 214
[HP(p-Tol)2]+ (85).
Yield: 1.40 g (67.5%); 13C NMR (CDCl3) d 26.0, 26.3
26.6, 27.4 29.3 (CH2, C6H11), 29.8, 31.9 (CH2,COD),
35.5 (CH2), 38.0 (CH, C6H11), 40.1 (CH), 97.6,
103.7 (@CH,COD), 129.4–129.9 (arom. C), 131.9
(arom. C), 136.9 (arom. C); 31P NMR (CDCl3) d
30.3 (d, J(P,Rh) = 141.5 Hz); C47H58BF4P2Rh (M =
874.62); FABMS
m/z (%) 787 [MꢀBF4]+, 679
[MꢀBF4ꢀCOD]+.
4.10. [Rh(COD)(2b)]BF4
Yield: 1.51 g (68.3%); 13C NMR (CDCl3) d 22.1 (CH3,
p-Tol), 27.5, 27.9, 28.1, 30.1, 30.8, (CH2, C6H11),
29.8, 31.8 (CH2,COD), 36.4 (CH2), 38.2 (CH, C6H11),
43.3 (CH), 98.2, 102.0 (@CH,COD), 129.5–129.9
(arom. C), 134.0–135.5 (arom. C), 138.6 (arom. C);
31P NMR (CDCl3) d 28.5 (d, J(P,Rh) = 141.5 Hz);
C51H66BF4P2Rh (M = 930.73); FABMS m/z (%) 843
[MꢀBF4]+, 735 [MꢀBF4ꢀCOD]+.
The compound was purified as its BH3 adduct. 1H NMR
(CDCl3) d 0.48–1.96 (28H, m), 2.35 (12H, d, CH3),
2.85 (2H, m), 3.42 (2H, m), 7.15–7.25 (8H, m, arom.
H), 7.66–7.74 (8H, m, arom. H); 13C NMR (CDCl3)
d 21.9 (CH3, p-Tol), 26.4–27.0, 27.8, 28.4, 29.4,
30.1, 30.8, (CH2, C6H11), 36.4 (CH2), 38.2 (CH,
C6H11), 129.8 (d, arom. C), 132.7–133.2 (arom. C),
141.5 (arom. C); 31P NMR (CDCl3) d 22.8 (m).
MS (70 eV) m/z (%) 437 (48), 436 (100), 434 [Mꢀ
P(p-Tol)2BH3]+ (12), 310 [P(p-Tol)2CH2Cy]+ (38), 228
[HP(p-Tol)2BH3]+ (64), 227 [P(p-Tol)2BH3]+ (29), 214
[HP(p-Tol)2]+ (17). C43H60B2P2 (M = 660.51); calcd:
C, 78.19; H, 9.16; P, 9.38; found: C, 77.51; H, 9.53; P,
8.68.
Acknowledgements
We are grateful for the financial support provided by the
Degussa AG (Hanau, Germany), the General Secretar-
iat of Research and Technology of Greece and the
Fonds der Chemischen Industrie. We thank Mrs. H.
Borgwaldt, Mrs. S. Buchholz and Mrs. S. Schareina
for skilled technical assistance.
4.7. General procedure for the preparation of
[Rh(COD)(ligand)]BF4
A solution of diphosphine 1b and 2a and b (2.37 mmol)
in THF (30 ml) was slowly added to a solution of
Rh(COD)acac (0.74 g, 2.37 mmol) in THF (30 ml).
The solution was stirred for 15 min. Then, a stoichio-
metric amount of aq 40% HBF4 was added and stirring
continued for another 15 min. The complex was precip-
itated with diethyl ether.
References
1. Asymmetric Catalysis on Industrial Scale; Blaser, H. U.,
Schmidt, E., Eds.; Wiley-VCH: Weinheim, 2004; Blaser,
H.-U.; Pugin, B.; Spindler, F. J. Mol. Catal. A: Chemical
2005, 231, 1–20.
2. Brown, J. M. In Comprehensive Asymmetric Catalysis;
Jacobsen, E. N., Pfaltz, A., Yamamoto, H., Eds.;
Springer: Berlin, 1999; Vol. I, pp 121–182; Ohkuma, T.;
Kitamura, M.; Noyori, R. In Catalytic Asymmetric
Synthesis; Ojima, I., Ed.; Wiley-VCH: New York, 2000;
pp 1–110.
4.8. [Rh(COD)(1b)]BF4
Yield: 1.93 g (75%); 13C NMR (CDCl3) d 20.4 (CH3),
28.0, 30.6 (CH2,COD), 34.5 (CH2), 39.2 (CH), 98.0,
100.4 (@CH,COD), 125.1–133.4 (arom. C), 136.7 (arom.
C), 138.2 (arom. C), 139.2 (arom. C); 31P NMR (CDCl3)
´
`
3. For recent reviews see: Dieguez, M.; Pamies, O.; Ruiz, A.;
´
Diaz, Y.; Castillon, S.; Claver, C. Coord. Chem. Rev. 2004,
d
23.5 (d, J(P,Rh) = 141.5 Hz); C51H54BF4P2Rh
248, 2165–2192; Au-Yueng, T. T.-L.; Chan, A. S. C.
Coord. Chem. Rev. 2004, 248, 2151–2164; Barbara, P.;
Bianchini, C.; Giambastiani, G.; Parisel, S. L. Coord.
Chem. Rev. 2004, 248, 2131–2150; Tang, W.; Zhang, X.
Chem. Rev. 2003, 103, 3029–3069.
(M = 918.64); FABMS m/z (%) 831 [MꢀBF4]+, 723
[MꢀBF4ꢀCOD]+.
Crystal structure analysis of [Rh(COD)(1b)]BF4: Data
were collected with a STOE-IPDS-diffractometer using
graphite-monochromated Mo Ka radiation. The struc-
ture was solved by direct methods (SHELXS-86)15 and
refined by full-matrix least-squares techniques against
F2 (SHELXL-93).16 XP (BRUKER AXS) was used for
structure representation. Space group C2221, ortho-
4. Review: Inoguchi, K.; Sakuraba, S.; Achiwa, K. Synlett
1992, 169–178.
5. RajanBabu, T. V.; Ayers, T. A.; Casalnuovo, A. L. J. Am.
Chem. Soc. 1994, 116, 4101–4102; RajanBabu, T. V.;
Ayers, T. A.; Halliday, G. A.; You, K. K.; Calabrese, J. C.
J. Org. Chem. 1997, 62, 6012–6028; RajanBabu, T. V.;
Radetich, B.; You, K. K.; Ayers, T. A.; Casalnuovo, A.
L.; Calabrese, J. C. J. Org. Chem. 1999, 64, 3429–3447.
6. (a) MacNeil, P. A.; Roberts, N. K.; Bosnich, B. J. Am.
Chem. Soc. 1981, 103, 2273–2280; (b) Herseczki, Z.;
˚
rhombic, a = 10.683(2), b = 31.762(6), c = 13.117(3) A,
3
V = 4451(2) A , Z = 4,
q
calcd = 1.371 g cmꢀ3
,
8340
˚
reflections measured, 2336 were independent of symme-