Lithium amides: Intra-aggregate complexation of lithium and entropy control of basicity

Angewandte Chemie - International Edition

Volumn 39, Issue 9, 2000, Pages 1643-1645

  Van Vliet, Gerbert L J ^a   Luitjes, Henri ^a   Schakel, Marius ^a   Klumpp, Gerhard W ^a  

^a VU UNIVERSITY AMSTERDAM   (Netherlands)

Author keywords

Aggregation; Amides; Basicity; Lithium; Thermodynamics

Indexed keywords

AMIDE; CARBONYL DERIVATIVE; LITHIUM; REAGENT;

ARTICLE; CHEMICAL REACTION; CHEMICAL STRUCTURE; COMPLEX FORMATION; ENTROPY; MOLECULAR STABILITY; THERMODYNAMICS;

EID: 0034595325     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/(SICI)1521-3773(20000502)39:9<1643::AID-ANIE1643>3.0.CO;2-9     Document Type: Article

References (26)

1. J. d'Angelo, Tetrahedron 1976, 32, 2979-2990; C. H. Heathcock in Comprehensive Carbanion Chemistry, Vol. B (Eds.: E. Buncel, T. Durst), Elsevier, New York, 1980, chap. 4; E. J. Corey, A. W. Gross, Tetrahedron Lett. 1984, 25, 495-498.
2. J. d'Angelo, Tetrahedron 1976, 32, 2979-2990; C. H. Heathcock in Comprehensive Carbanion Chemistry, Vol. B (Eds.: E. Buncel, T. Durst), Elsevier, New York, 1980, chap. 4; E. J. Corey, A. W. Gross, Tetrahedron Lett. 1984, 25, 495-498.
3. J. d'Angelo, Tetrahedron 1976, 32, 2979-2990; C. H. Heathcock in Comprehensive Carbanion Chemistry, Vol. B (Eds.: E. Buncel, T. Durst), Elsevier, New York, 1980, chap. 4; E. J. Corey, A. W. Gross, Tetrahedron Lett. 1984, 25, 495-498.
4. For example, H. Ahlbrecht, G. Schneider, Tetrahedron 1986, 42, 4729-4741, and references therein.
5. If the conjugate acids HA do not partake in special interactions they can be assigned equal relative free energies and equal relative enthalpies.
6. G. L. J. van Vliet, F. J. J. de Kanter, M. Schakel, G. W. Klumpp, A. L. Spek, M. Lutz, Chem. Eur. J. 1999, 5, 1091-1094.
7. G. L. J. van Vliet, unpublished results.
8. G. Hilmersson, P. I. Arvidsson, Ö. Davidsson, Organometallics 1997, 16, 3352-3362.
9. In pentane, the reaction order of THF, added to the system 2-exo-bromonorbornane + 3-Li, is close to one-half. This indicates the presence, in the transition state, of one molecule of THF per two atoms of lithium (G. L. J. van Vliet, unpublished results).
10. 1.
11. Compare I. S. Antipin, R. F. Gareev, A. N. Vedernikov, A. I. Konovalov, Zh. Org. Khim. 1989, 25, 1153-1160.
12. Li,THF,30 C is based on that of TPMH.
13. 2NH and 3-H and may have similar origins.
14. For the effects of intramolecular complexation on alkyllithium compounds, see R. F. Schmitz, M. Schakel, M. Vos, G. W. Klumpp, Chem. Commun. 1998, 1099-1100, and references therein.
15. 3CLi solvation, see C. Lambert, P. von R. Schleyer, Methoden Org. Chem. (Houben-Weyl), 4th ed. 1952-, Vol. E19d, 1993, p. 68.)
16. 3CLi solvation, see C. Lambert, P. von R. Schleyer, Methoden Org. Chem. (Houben-Weyl), 4th ed. 1952-, Vol. E19d, 1993, p. 68.)
17. 3CLi solvation, see C. Lambert, P. von R. Schleyer, Methoden Org. Chem. (Houben-Weyl), 4th ed. 1952-, Vol. E19d, 1993, p. 68.)
18. KMRAI 3-Li·2THF (3)
19. 2 and 1-H exhibited separate spectra of the two species. Warming led to extensive coalescence that prevented identification of any new species.
20. 6 times higher.
21. + with intra-aggregate complexation (e.g., D. Sato, H. Kawasaki, I. Shimada, Y. Arata, K. Okamura, T. Date, K. Koga, J. Am. Chem. Soc. 1992, 114, 761-763).
22. According to, both experimental results and calculations, the lithium atom in dimers of lithium amides is tricoordinate: F. E. Romesberg, D. B. Collum, J. Am. Chem. Soc. 1992, 114, 2112-2121; B. L. Lucht, D. B. Collum, J. Am. Chem. Soc. 1995, 117, 9863-9874.
23. According to, both experimental results and calculations, the lithium atom in dimers of lithium amides is tricoordinate: F. E. Romesberg, D. B. Collum, J. Am. Chem. Soc. 1992, 114, 2112-2121; B. L. Lucht, D. B. Collum, J. Am. Chem. Soc. 1995, 117, 9863-9874.
24. 1, E. M. Arnett, K. D. Moe, J. Am. Chem. Soc. 1991, 113, 7068-7069).
25. 1 per lithium atom.
26. [5] is exceptional. Due to the intra-aggregate mode of complexation, adverse effects of entropy loss and steric crowding, both disfavoring intermolecular tetracoordination of THF to LiA dimers, are minimal.