LETTER
On the Source of Transfer of Stereochemical Information
909
Figure 1 MM2 Calculations for bicyclic normal ligands
Table 2 Enantioselectivity of Oxazolidin-2-one Synthesis Using References and Notes
Normal Ligands (eq. 1)a
(
1) For some recent references, see: Trost, B.M.; Surivet, J.-P.
Angew. Chem. Int. Ed. 2000, 39, 3122. Trost, B.M.; Surivet,
J.-P. J. Am. Chem. Soc. 2000, 122, 6291. Trost, B.M.;
Schroeder, G.M. J. Am. Chem. Soc. 2000, 122, 3785. Trost,
B.M.; Tsui, H.-C.; Toste, F.D. J. Am. Chem. Soc. 2000, 122,
3534. Trost, B.M.; Schroeder, G.M. J. Org. Chem. 2000, 65,
1569.
(
(
2) For reviews, see: Trost, B.M.; Lee, C.B. in "Catalytic
Asymmetric Synthesis," Ojima, I., Ed.; Sec. Ed.; Wiley-VCH:
New York, 2000, pp. 593-650. Trost, B.M.; Van Vranken,
D.L. Chem. Rev. 1996, 96, 395. Trost, B.M. Acc. Chem. Res.
1996, 29, 355.
3) (a) Trost, B.M.; Van Vranken, D.L.; Bingel, C. J. Am. Chem.
Soc. 1992, 114, 9327. (b) Trost, B.M.; Breit, B.; Organ, M.G.
Tetrahedron Lett. 1994, 35, 5817.
aIn all cases, reactions were performed as shown in eq. 1 except if
noted otherwise.
b
Taken from ref. 3a.
Clearly, no single factor can explain the complex phe-
nomenon involved in transferring stereochemical infor-
mation over large distances in these ligands. Furthermore,
the factors that are important in the normal series appear
to be quite different than those mainly influencing the in-
vertomer series. In the normal series, buttressing between
the diphenylphosphinobenzoyl moiety and the chiral scaf-
fold does appear to affect directly the ee and presumably
the nature of the chiral pocket. Designing ligands to en-
hance this buttressing interaction then may create the next
generation of chiral ligands for AAA reactions.
(
(
(
4) Also see: Trost, B.M.; Patterson, D.E. J. Org. Chem. 1998, 63,
1339.
5) Trost, B.M.; Breit, B.; Peukert, S.; Zambrano, J.; Ziller, J.W.
Angew. Chem. Int. Ed. Engl. 1995, 34, 2386.
6) Trost, B.M.; Van Vranken, D.L. J. Am. Chem. Soc. 1993, 115,
444.
(7) Yamamoto, H.; Iwanaga, K.; Furuta, K. Org. Synth. 1989, 67,
76. Walborsky, M.H.; Sugita, T.; Inouye, Y. Tetrahedron
1964, 20, 1695.
(
8) Cooper, M.K.; Downes, J.M.; Duckworth, P.A.; Soucer,
M.D.; Powell, R.J.; Kerby, M.C. Inorg. Synth. 1989, 25, 129.
9) For the resolution of the dicarboxylic acid, see: Goldsworthy,
L.J. J. Chem. Soc. 1924, 2013. For butadiene
(
photodimerization, see: De Boer, C.D.; Turro, N.J.;
Hammond, G.S. Org. Synth. Coll. Vol. V 1973, 528-532.
Acknowledgement
We thank the National Institutes of Health and the National Science
Foundation for their generous support of our programs and the IN-
TEVEP (Technological Venezuelan Institute of Petroleum) for a
partial fellowship for J.L.Z. Financial support by the Feodor-Lynen
Fellowship for W.R. is gratefully acknowledged. Mass spectra were
obtained from the Mass Spectrometry Facility, University of San
Francisco, supported by the NIH Division of Research Resources.
(10) Yamamoto, H.; Iwanaga, K.; Furuta, K. Tetrahedron Lett.
1986, 27, 4507.
(11) All new compounds have been satisfactorily characterized.
(12) Weinstock, J. J. Org. Chem. 1961, 26, 3511.
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Synlett 2001, SI, 907–909 ISSN 0936-5214 © Thieme Stuttgart · New York