Origins of selectivity in conjugate additions of alkenylphosphonates to lithiated bislactim ethers: A semiempirical study

Tetrahedron Asymmetry

Volumn 7, Issue 12, 1996, Pages 3335-3338

  Ojea, Vicente ^a   Ruiz, María ^a   Vilar, Juan ^a   Quintela, José M ^a  

^a UNIVERSITY OF A CORUÑA   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

ORGANOLITHIUM COMPOUND; PHOSPHONIC ACID DERIVATIVE;

ARTICLE; CHEMICAL MODIFICATION; CONFORMATION; CONJUGATION; DRUG STRUCTURE; DRUG SYNTHESIS; PRIORITY JOURNAL; STEREOCHEMISTRY;

EID: 0030561195     PISSN: 09574166     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0957-4166(96)00436-3     Document Type: Article

References (32)

1. 1. a. CNS Neurotransmiters and Neuromodulators: Glutamate. Stone, T.W. Ed., CRC Press Inc., New York, 1995.
2. b. Knöpfel, T.; Kuhn, R.; Allgeier, H. J. Med. Chem. 1995, 38, 1417.
3. 2. a. Berkowitz, D.B.; Eggen, MJ.; Shen, Q.; Schoemaker, R.K. J. Org. Chem. 1996, 61, 4666.
4. b. Shapiro, G.; Buechler, D.; Enz, A.; Pombo-Villar, E. Tetrahedron Lett. 1994, 55, 1173.
5. 3. a. Shapiro, G.; Buechler, D.; Ojea, V.; Pombo-Villar, E.; Ruiz, M.; Weber, H-P. Tetrahedron Lett. 1993, 34, 6255.
6. b. Ojea, V.; Ruiz, M.; Shapiro, G. Pombo-Villar, E. Tetrahedron Lett. 1994, 35, 3273.
7. c. Ruiz, M.; Ojea, V.; Shapiro, G.; Weber, H-P.; Pombo-Villar, E. Tetrahedron Lett. 1994, 35, 4551.
8. d. Ojea, V.; Fernández, M.C.; Ruiz, M.; Quintela, J.M. Tetrahedron Lett. 1996, 37, 5801.
9. 4. Schöllkopf, U.; Pettig, D.; Busse, U.; Egert, E.; Dyrbusch, M. Synthesis 1985, 737.
10. 5. Heathcock, C.H.; Oare, D.A. J. Org. Chem. 1990, 55, 132, and references cited therein.
11. 6. Bernardi, A. Gazz. Chim. Ital. 1995, 125, 539 and references cited therein.
12. 7. a. Dewar, M.J.S.; Thiel, W.; J. Am. Chem. Soc. 1977, 99, 4899.
13. b. Stewart, J.J.P. J. Comp. Chem. 1990, 10, 209.
14. 8. Romesberg, F.E.; Collum, D.B. J. Am. Chem. Soc. 1995, 117, 2166, and references cited therein
15. 9. a. Koch, R.; Wiedel, B.; Anders, E. J. Org. Chem. 1996, 61, 2523.
16. b. Koch, R.; Anders, E. J. Org. Chem. 1995, 60, 5861.
17. c. Anders, E.; Koch, R.; Freunscht, P. J. Comp. Chem. 1993, 14, 1301.
18. 10. The X ray structure of a lithiated bislactim derivative was determined as a trisolvated dimmeric aggregate, but cryoscopic experiments have shown an average degree of aggregation of 1.15 for the same compound at low temperature diluted ethereal solutions, see: Seebach, D.; Bauer, W.; Hansen, J.; Laube, T.; Schweizer, W.B.; Dunitz, J.D. J. Chem. Soc., Chem. Commun. 1984, 853.
19. 12c were used as graphical interfaces for preparing, visualizing and comparing geometries.
20. 12. a. Steward, J.J.P. MOPAC93, Fujitsu Limited, Tokyo, Japan, 1993.
21. b. PCModel version 5, from Serena Software, Bloomington, IN 47402, USA.
22. c. CS Chem3D Pro, Cambridge Soft. Corporation, Cambridge, MA 02139, USA.
23. 13. Similar process for a trisolvated enolate proceeds through a trigonal bipyramidal intermediate to afford A8 and a free water molecule, in a quite less exothermic fashion (ΔH°= -4.46 (MNDO), -8.26 (PM3) Kcal/mol, see ref 18). Some uncertainty about this step remains, resulting from the known tendency of semiempirical methods to overestimate the stabilities of adduct complexes. See Opitz, A.; Koch, R.; Katritzky, A.R.; Fan, W.-Q.; Anders, E. J. Org. Chem. 1995, 60, 3743.
24. 14. The global minimum for chelates 8a-c showed a s-trans configuration. Similar stabilization of s-trans conformation by metal coordination was found for unsaturated aldehydes. See Houk et al J. Am. Chem. Soc. 1987, 109, 14, and Schereiber Angew. Chem. Internat. Ed. Eng. 1990, 29, 256.
25. 14. The global minimum for chelates 8a-c showed a s-trans configuration. Similar stabilization of s-trans conformation by metal coordination was found for unsaturated aldehydes. See Houk et al J. Am. Chem. Soc. 1987, 109, 14, and Schereiber Angew. Chem. Internat. Ed. Eng. 1990, 29, 256.
26. 5
27. 16. Kranz, M.; Denmark, S.E. J. Org. Chem. 1995, 60, 5867, and references cited therein.
28. 17. Sevin, A; Tortajada, J.; Pfau, M. J. Org. Chem. 1986, 51, 2671. A compact approach was also proposed in other conjugated additions: Cavé, C.; Desmaële, D.; d'Angelo, J.; Riche, C.; Chiaroni, A. J. Org. Chem. 1996, 61, 4361.
29. 17. Sevin, A; Tortajada, J.; Pfau, M. J. Org. Chem. 1986, 51, 2671. A compact approach was also proposed in other conjugated additions: Cavé, C.; Desmaële, D.; d'Angelo, J.; Riche, C.; Chiaroni, A. J. Org. Chem. 1996, 61, 4361.
30. 195 A(6+7) -353.32 -358.45 0 B11 -347.39 -373.86 1 (-398.1) 13.43 0.00 A8 -363.35 -376.25 0 B12 -343.68 -370.81 1 (-378.0) 16.48 3.14 A9 -343.98 -362.32 1 (-389.7) 13.93 0.00 C13 -322.42 -343.05 1 (-367.5) 19.53 5.14 A10 -343.24 -360.91 1 (-384.7) 15.34 1.71 C14 -327.28 -348.40 1 (-488.0) 12.86 0.00 C15 -326.49 -346.80 1 (-502.2) 14.53 1.41
31. #(relaxed-compact)prol,4 = 1.10 Kcal/mol.
32. #(relaxed-compact)prol,6 = 1.48 Kcal/mol (PM3) ) indicates a useful level of facial discrimination. In agreement with this computational based prediction, preliminary experiments in this laboratory have revealed the additions of lithiated bislactim ethers to stereogenic 1E,3E-and 1Z,3E-butadienylphosphonates as very promising stereoselective processes.