The most twisted amide: Structure and reactions

Angewandte Chemie - International Edition

Volumn 37, Issue 6, 1998, Pages 785-786

  Kirby, Anthony J ^a   Komarov, Igor V ^a,b   Wothers, Peter D ^a   Feeder, Neil ^a  

^a UNIVERSITY OF CAMBRIDGE   (United Kingdom)

^b TARAS SHEVCHENKO NATIONAL UNIVERSITY OF KYIV   (Ukraine)

Author keywords

Amides; Cage compounds; Ketones; Stereo electronic effects

Indexed keywords

EID: 0031901521     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/(SICI)1521-3773(19980403)37:6<785::AID-ANIE785>3.0.CO;2-J     Document Type: Article

References (16)

1. K. S. Jeong, K. Paris, P. Ballester, J. Rebek, Jr., Angew. Chem. 1990, 102, 550-551; Angew. Chem. Int. Ed. Engl. 1990, 29, 555-556. We are grateful to Prof. Rebek, Jr. for detailed experimental instructions for the preparation of 2.
2. K. S. Jeong, K. Paris, P. Ballester, J. Rebek, Jr., Angew. Chem. 1990, 102, 550-551; Angew. Chem. Int. Ed. Engl. 1990, 29, 555-556. We are grateful to Prof. Rebek, Jr. for detailed experimental instructions for the preparation of 2.
3. Compound 3: H. Pracejus, Chem. Ber. 1959, 92, 988-993; Compound 4: E. I. Levkoeva, E. S. Nikitskaya, L. N. Yakhontov, Khim. Geterotsikl. Soedin. 1971, 3, 378-384; Compound 5: G. M. Blackburn, C.J. Skaife, I. T. Kay, J. Chem. Res. Miniprint 1980, 3650-3669; V. Somayaji, R. S. Brown, J. Org. Chem. 1986, 51, 2676-2686.
4. Compound 3: H. Pracejus, Chem. Ber. 1959, 92, 988-993; Compound 4: E. I. Levkoeva, E. S. Nikitskaya, L. N. Yakhontov, Khim. Geterotsikl. Soedin. 1971, 3, 378-384; Compound 5: G. M. Blackburn, C.J. Skaife, I. T. Kay, J. Chem. Res. Miniprint 1980, 3650-3669; V. Somayaji, R. S. Brown, J. Org. Chem. 1986, 51, 2676-2686.
5. Compound 3: H. Pracejus, Chem. Ber. 1959, 92, 988-993; Compound 4: E. I. Levkoeva, E. S. Nikitskaya, L. N. Yakhontov, Khim. Geterotsikl. Soedin. 1971, 3, 378-384; Compound 5: G. M. Blackburn, C.J. Skaife, I. T. Kay, J. Chem. Res. Miniprint 1980, 3650-3669; V. Somayaji, R. S. Brown, J. Org. Chem. 1986, 51, 2676-2686.
6. Compound 3: H. Pracejus, Chem. Ber. 1959, 92, 988-993; Compound 4: E. I. Levkoeva, E. S. Nikitskaya, L. N. Yakhontov, Khim. Geterotsikl. Soedin. 1971, 3, 378-384; Compound 5: G. M. Blackburn, C.J. Skaife, I. T. Kay, J. Chem. Res. Miniprint 1980, 3650-3669; V. Somayaji, R. S. Brown, J. Org. Chem. 1986, 51, 2676-2686.
7. -3, respectively. The C=O group is disordered over two sites: The bond lengths quoted for C=O and C-N represent the weighted mean values from the two disordered fragments. Crystallographic data (excluding structure factors) for the structure reported in this paper have been deposited with the Cambridge Crystallographic Data Center as supplementary publication no. CCDC-100711. Copies of the data can be obtained free of charge on application to CCDC, 12 Union Road, Cambridge CB21EZ (fax: (+44)1223-336-033; e-mail: deposit@ccdc.cam.ac.uk).
8. The figure of 325.7 is very similar to those observed for acyclic tertiary amines, and identical to that measured for the sum of the three bond angles at the N atoms of diazabicyclooctane: S. Sorriso in The Chemistry of Functional Groups, Supplement F, Part 1 (Ed.: S. Patai), Wiley-Interscience, Chichester, 1982, p. 1.
9. F. H. Allen, O. Kennard, D. G. Watson, L. Brammer, A. G. Orpen, R. Taylor, J. Chem. Soc. Perkin Trans. 2 1987, S1-S19. The effect of the adjacent nitrogen appears to be to shorten the C=O bond in 1 with respect to that in a simple ketone: The mean value for cyclohexanones is 1.211(9) Å.
10. The angle of twist (not a simple torsion angle) was defined by F. K. Winkler, J. D. Dunitz, J. Mol. Biol. 1971, 59, 169.
11. We consider as simple amides compounds with only one N-C=O bond. The rotational barrier is significantly reduced if a second C=O (or C=S) group is attached to the same nitrogen atom.
12. Relevant known structures: A. Greenberg, C. A. Venanzi, J. Am. Chem. Soc. 1993, 115, 6951-6957.
13. [10] and was the primary objective of this work. Our structural and conformational studies on this compound will be reported shortly.
14. C. L. Perrin, Tetrahedron, 1995 51, 11 901-11 935.
15. [12] and derive further stabilization from the adamantane framework in our system.
16. N. H. Werstiuk, R. S. Brown, Q. Wang, Can. J. Chem. 1996, 74, 524-532.