Synthesis and X-ray structure of a tris(trimethylsilyl)oxacalix[3]arene

New Journal of Chemistry

Volumn 20, Issue 4, 1996, Pages 427-432

  Hampton, Philip D ^a   Daitch, Charles E ^a   Duesler, Eileen N ^a  

^a UNIVERSITY OF NEW MEXICO   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000330340     PISSN: 11440546     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article

References (23)

1. (a) Suzuki K., Minami H., Yamagata Y., Fujii S., Tomita K., Asfari Z., Vicens J., Acta Cryst., 1992, C48, 350-352.
2. (b) Gutsche C. D., Bauer L. J., J. Amer. Chem. Soc., 1985, 107, 6052.
3. Hampton P. D., Bencze Z., Tong W., Daitch C. E., J. Org. Chem., 1994, 59, 4838.
4. (a) Dhawan B., Gutsche C. D., J. Org. Chem., 1983, 48, 1536;
5. (b) Zerr P., Mussrabi M., Vicens J., Tetrahedron Lett., 1991, 32, 1879.
6. Khrifi S., Guelzim A., Baert F., Mussrabi M., Asfari Z., Vicens J., Acta Cryst., 1995, C51, 153.
7. (a) Hampton P. D., Daitch C. E., Alam T. M., Bencze Z., Rosay M., Inorg. Chem., 1994, 33, 4750;
8. (b) Daitch C. E., Hampton P. D., Duesler E. N., Inorg. Chem., 1995, 34, 5641.
9. (a) Gutsche C. D., Levine J. A., J. Amer. Chem. Soc., 1982, 104, 2652;
10. (b) Gutsche C. D., Dhawan B., Levine J. A., Hyun No, K., Bauer L. J., Tetrahedron, 1983, 39, 409;
11. (c) Gutsche C. D., Bauer L. J., J. Amer. Chem. Soc., 1985, 107, 6059;
12. (d) Gutsche C. D., Pagoria P. F., J. Org. Chem., 1985, 50, 5795.
13. Abbreviations: BSTFA: bis(trimethylsilyl)trifluoroacetamide, TMSIM: 1-(trimethylsilyl)imidazole, and TMSTF: trimethylsilyl-trifluoromethanesulfonate.
14. SHELXTL PC, Siemens Analytical X-Ray Instruments, Inc., 1990.
15. International Tables for X-ray Crystallography; Kynoch: Birmingham, England, 1974; Vol. IV, 99-100, 149.
16. The two "sides" of the macrocycle ligand are defined with respect to a hypothetical planar macrocycle ligand.
17. (a) Araki K., Inada K., Otsuka H., Shinkai S., Tetrahedron, 1993, 49, 9465;
18. (b) Araki K., Hashimoto N., Otsuka H., Shinkai S., J. Org. Chem., 1993, 58, 5958;
19. (c) Takeshita M., Shinkai S., Chem. Lett., 1994, 125.
20. 3, a singlet and a pair of meta-coupled doublets (2:2:2 ratio) are observed.
21. Atomic coordinates have been deposited with the Cambridge Crystallographic Data Centre and can be obtained on request at the CCDC, Union Road, Cambridge CB2 IEZ, UK. Structure factors and thermal parameters have been deposited with the British Library, Document Supply Centre at Boston Spa, Wetherby, West Yorkshire, UK, as supplementary publication No. = SUP 90399 and is available on request from the Document Supply Centre.
22. Several conformations are possible for a monosilylated intermediate. The "cone" conformation would have the two phenolic groups on the same side of the macrocycle as the trimethylsilyl group; silylation of this conformation would result in the "cone" isomer 3. Two "partial-cone"conformations are possible where one ("partial-cone A") or two ("partial-cone B") phenol groups are on the opposite side of the macrocycle as the trimethylsilyl group. Both of these conformations would yield the "partial-cone" isomer 2 on complete silylation, and both have the trimethylsilyl group close to one or two para-substituents on the adjacent aryl rings. Molecular modeling (PCMODEL®, Serena Software, Bloomington, IN) of a hydrogen-bonded, monosilylated intermediate (R = H) indicates that the lowest energy conformation is the "partial-cone B". The "cone" conformation is only slightly higher in energy (∼1 - 2 kcal/mol), and the "partial-cone A" is the highest energy conformation.
23. -1; reference 2.