Cationic Aqua Complexes of the C2-Symmetric trans-Chelating Ligand (R,R)-4,6-Dibenzofurandiyl-2,2′-bis(4-phenyloxazoline). Absolute Chiral Induction in Diels-Alder Reactions Catalyzed by Water-Tolerant Enantiopure Lewis Acids

Journal of Organic Chemistry

Volumn 62, Issue 19, 1997, Pages 6454-6455

  Kanemasa, Shuji ^a   Oderaotoshi, Yoji ^a   Yamamoto, Hidetoshi ^a   Tanaka, Junji ^a   Wada, Eiji ^a   Curran, Dennis P ^b  

^a KYUSHU UNIVERSITY   (Japan)

^b UNIVERSITY OF PITTSBURGH   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0001696290     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo970906w     Document Type: Article

References (20)

1. (1)(a) Odenkirk, W.; Bosnich, B. J. Chem. Soc., Chem. Commun. 1995, 1181-1182.
2. (b) Hollis, T. K.; Robinson, N. P.; Bosnich, B. J. Am. Chem. Soc. 1992, 114, 5464-6546.
3. Odenkirk, W.; Rheingold, A. L.; Bosnich, B. J. Am. Chem. Soc. 1992, 114, 6392-6398.
4. (a) Sawamura, M.; Kuwano, R.; Ito, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 111-113.
5. (b) Sawamura, M.; Hamashima, H.; Ito, Y. J. Am. Chem. Soc. 1992, 114, 8295-8296 and references cited therein.
6. (a) Nishiyama, H.; Itoh, Y.; Sugawara, Y.; Matsumoto, H.; Aoki, K.; Itoh, K. Bull. Chem. Soc. Jpn. 1995, 68, 1247-1262.
7. (b) Park, S.-B.; Murata, K.; Matsumoto, H.; Nishiyama, H. Tetrahedron: Asymmetry 1995, 6, 2487-2494,
8. (c) Nishiyama, H.; Yamaguchi, S.; Kondo, M.; Itoh, K. J. Org. Chem. 1992, 57, 4306-4309.
9. (d) Nishiyama, H.; Park, S.-B.; Itoh, K. Tetrahedron: Asymmetry 1992, 8, 1029-1034.
10. (e) Nishiyama, H.; Kondo, M. Nakamura, T.; Itoh, K. Organometallics 1991, 10, 500-508.
11. (f) Nishiyama, H.; Sakaguchi, H.; Nakamura, T.; Horihata, M.; Kondo, M.; Itoh, K. Organometallics 1989, 8, 846-848.
12. (a) Evans, D. A.; Murry, J. A.; Kozlowski, M. C. J. Am. Chem. Soc. 1996, 118, 5814-5815.
13. (b) Evans, D. A.; Lectka, T.; Miller, S. J. Tetrahedron Lett. 1993, 7027-7030.
14. 2; cyclization with aqueous NaOH.
15. The authors have deposited atomic coordinates for the structures of 1 and 4 with the Cambridge Crystallographic Data Centre. The coordinates can be obtained on request from The Director, Cambridge Crystallo graphic Data Centre, University Chemical Laboratory, Lensfield Road, Cambridge, CB2 1EW, U.K. The coordinates are also attached as Supporting Information.
16. 2O (10 mol %) is treated with 1 (10 mol %) in dichloromethane (0.16 M with respect to 2a) at room temperature for 2 h during which time the insoluble nickel salt is completely dissolved. After 2a is introduced, the mixture is cooled down to -40 °C, and excess (10 equiv) of cyclopentadiene is allowed to react. The reaction is continued at -40 °C for 14 h. Usual hydrolytic workup with saturated aqueous ammonium chloride gives 96% yield of (1S,4S,5S)-(bicyclo[2.2,1]hept-2-ene-5-carbonyl)-3-(2-oxazolidinone) (3, endo:exo = 97:3, endo 100% ee).
17. Strong coordination of triflate ligands to the magnesium ion may be a reason for the poor catalytic activity (Evans, D. A.; Murry, J. A.; von Matt, P.; Norcross, R. D.; Miller, S. J. Angew. Chem., Int. Ed. Engl. 1995, 34, 798-800).
18. The 5 position of the oxazoline ring is activated by the coordination of magnesium ion so that the nuceophilic counteranion attacks to cause the ring opening.
19. 2 complex does not undergo dissociation into components even in the presence of 3-acetyl-2-oxazolidine.
20. 2O complex of the 4-substituted isopropylidene-2,2′-bisoxazoline forms these two transition structures depending upon the steric nature of 4-substituent (unpublished results).