3
720
0
0
(
2 -hydroxy-5 -methylphenyl)-1-phenylethene could infer a new type of shape selectivity: among the
22
rhodium atoms embodied in the HSA matrix the most active ones could be coordinated to the residue
Trp-214 (corresponding to the tryptophan moiety)1
8–20
and hence located in the hollow shown in Fig.
1; therefore it is very difficult for bulky olefins to reach a metal center to form a catalytically active
olefin–rhodium(I) species.
Currently, studies devoted to elucidate the HSA–Rh(I) structure,23 in particular, to characterize the
rhodium binding sites are in progress.
References
1
2
3
4
. Cornils, B. J. Mol. Catal. A: Chem. 1999, 143, 1.
. Aqueous-Phase Organometallic Catalysis; Cornils, B.; Herrmann, W. A., Eds.; VCH: Weinheim, 1999.
. Schreuder Goedheijt, M.; Kamer, P. C. J.; Van Leeuwen, P. W. N. M. J. Mol. Catal. A: Chem. 1998, 134, 243.
. Sandeer, A. J.; Slagt, V. F.; Reek, J. N. H.; Kamer, P. C.; Van Leeuwen, P. W. N. M. J. Chem. Soc., Chem. Commun. 1999,
1
633.
5
6
7
. Joo’, F.; Katho’, A. J. Mol. Catal. A: Chem. 1997, 116, 3.
. Kuntz, E. G. CHEMTECH 1987, 17, 570.
. Frohning, C. D.; Kohlpaintner, C. W. In Applied Homogeneous Catalysis with Organometallic Compounds; Cornils, B.;
Herrmann, W. A., Eds.; VCH: Weinheim, 1996; Vol. 1, p. 80.
8
9
. Ding, H.; Kang, J.; Hanson, B. E.; Kohlpaintner, C. W. J. Mol. Catal. A: Chem. 1997, 124, 21.
. Herrmann, W. A.; Kohlpaintner, C. W.; Monetsberger, R. B.; Bohrmann, H.; Kottermann, H. J. Mol. Catal. A: Chem. 1995,
9
7, 65.
1
1
1
0. Paganelli, S.; Zanchet, M.; Marchetti, M.; Mangano, G. J. Mol. Catal. A: Chem., in press.
1. Son, S. U. K.; Wook Han, J.; Kenn Chung, Y. J. Mol. Catal. A: Chem. 1998, 135, 35.
2. Fremy, G.; Castagnet, Y.; Grzybek, R.; Monflier, E.; Montreux, A.; Trzeciak, A. M.; Ziolkowski, R. J. Organomet. Chem.
1
995, 505, 11.
1
1
1
1
1
1
1
2
3. Chen, J.; Alper, H. J. Am. Chem. Soc. 1997, 119, 893.
4. Ajjou, A. N.; Alper, H. J. Am. Chem. Soc. 1998, 120, 1466.
5. Peters Jr., T. Clin. Chem. 1977, 23, 5.
6. Giraldi, T.; Sava, G.; Mestroni, G.; Zassinovich, G.; Stolfa, D. Chem.-Biol. Interact. 1978, 22, 231.
7. Lo, J. M.; Pillai, M. R.; John, C. S.; Trantrer, D. E. Int. J. Rad. Appl. Instrum. [A] 1990, 41, 63.
8. Trynda, L.; Pruchnik, F. J. Inorg. Biochem. 1995, 58, 69.
9. Trynda, L.; Pruchnik, F. J. Inorg. Biochem. 1997, 66, 187.
0. Poumia Espòsito, B.; Faljani-Alàsio, A.; Silva de Menezes, J. F.; Felinto de Brito, H.; Majjar, R. J. Inorg. Biochem. 1999,
7
5, 55.
2
1. The enantiomeric excesses were determined by chiral GC analysis using a 25 m silica capillary column ID 0.25 mm, film
thickness 0.25 mm, stationary phase diethyltertbutylsilyl-β-CDX 30%-PS086 70% (initial temperature 50°C, temperature
rate 2°C/min up to 150°C).
22. To determine the number of rhodium g-atoms per mol of HSA a complex HSA–Rh(I) was prepared as follows: to HSA
2
(32 mg) dissolved in deoxygenated water (20 mL) Rh(CO) (acac) (1 mg) was added. This solution was stirred for 10 min
under an inert atmosphere at 40°C; the color of the solution changed from purple-red to pale yellow. Then acetone (80
mL) was added and the mixture evaporated at reduced pressure. The oil residue was crystallized from methanol to yield a
microcrystalline yellow solid (28 mg; mp 250–252°C dec.). The IR spectrum (KBr) of the complex exhibits two carbonyl
−
1
bands at 2006 and 2083 cm suggesting that Rh(I) carbonyl complexes are present. The assay of rhodium bonded per mol
of HSA was performed by ICP-MS; this analysis shows that HSA binds ca. 30 equiv. of Rh(I).
3. PDB protein data bank (http://www.rcsb.org/pdb/index.html).
2