Structure and stereodynamics of N-methyl-N-9-triptycylacetamide: Pyramidal amide nitrogen in the crystalline state

Chemistry Letters

Volumn , Issue 7, 1997, Pages 605-606

  Yamamoto, Gaku ^a   Murakami, Hiroaki ^a   Tsubai, Natsuko ^a   Mazaki, Yasuhiro ^a  

^a KITASATO UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0031491344     PISSN: 03667022     EISSN: None     Source Type: Journal    
DOI: 10.1246/cl.1997.605     Document Type: Article

References (17)

1. W. E. Stewart and T. H. Siddall, III, Chem. Rev., 70, 517 (1970); M. Ōki, "Applications of Dynamic NMR Spectroscopy to Organic Chemistry," VCH, New York (1985), Chap. 2; M. Pinto, in "Acyclic Organonitrogen Stereodynamics," ed by J. B. Lambert and Y. Takeuchi, VCH, New York (1992), Chap. 5.
2. W. E. Stewart and T. H. Siddall, III, Chem. Rev., 70, 517 (1970); M. Ōki, "Applications of Dynamic NMR Spectroscopy to Organic Chemistry," VCH, New York (1985), Chap. 2; M. Pinto, in "Acyclic Organonitrogen Stereodynamics," ed by J. B. Lambert and Y. Takeuchi, VCH, New York (1992), Chap. 5.
3. W. E. Stewart and T. H. Siddall, III, Chem. Rev., 70, 517 (1970); M. Ōki, "Applications of Dynamic NMR Spectroscopy to Organic Chemistry," VCH, New York (1985), Chap. 2; M. Pinto, in "Acyclic Organonitrogen Stereodynamics," ed by J. B. Lambert and Y. Takeuchi, VCH, New York (1992), Chap. 5.
4. See for example: K. B. Wiberg and C. M. Breneman, J. Am. Chem. Soc., 114, 831 (1992); A. Greenberg, D. T. Moore, and T. D. DuBois, J. Am. Chem. Soc., 118, 8658 (1996).
5. See for example: K. B. Wiberg and C. M. Breneman, J. Am. Chem. Soc., 114, 831 (1992); A. Greenberg, D. T. Moore, and T. D. DuBois, J. Am. Chem. Soc., 118, 8658 (1996).
6. a) G. Yamamoto, H. Higuchi, M. Yonebayashi, and J. Ojima, Chem. Lett., 1994, 1911.
7. b) G. Yamamoto, H. Higuchi, M. Yonebayashi, Y. Nabeta, and J. Ojima, Tetrahedron, 52, 12409 (1996).
8. G. Yamamoto, K. Kuwahara, and K. Inoue, Chem. Lett. , 1995, 351; G. Yamamoto, H. Higuchi, M. Yonebayashi, Y. Nabeta, and J. Ojima, Chem. Lett., 1995, 853.
9. G. Yamamoto, K. Kuwahara, and K. Inoue, Chem. Lett. , 1995, 351; G. Yamamoto, H. Higuchi, M. Yonebayashi, Y. Nabeta, and J. Ojima, Chem. Lett., 1995, 853.
10. 3, 23°C, 75.5 MHz) δ 174.5 (Z) and 178.0 (E).
11. -3, R = 0.056, 4787 unique reflections with I>2.0σ(I). For both compounds, the structures were solved by direct method (SHELX-86) and all hydrogen atoms were located by difference Fourier synthesis. Full-matrix least-squares refinement was performed with anisotropic non-hydrogen atoms and isotropic hydrogen atoms.
12. Pyramidal nitrogens in lactams are often documented. See for example: T. G. Lease and K. J. Shea, J. Am. Chem. Soc., 115, 2248 (1993).
13. Theoretical calculations well reproduce the pyramidal nitrogen atom indicating that the pyramidality is the intrinsic property of the molecule and not due to intermolecular interactions.
14. -1 for the E→Z process (Temp/°C): 300 (62), 170 (52), 80 (44), 40 (38), 18 (28), 12 (23), 4.1 (12.5), and 1.1 (2).
15. K. B. Wiberg, P. R. Rablen, D. J. Rush, and T. A. Keith, J. Am. Chem. Soc., 117, 4261 (1995).
16. Dynamic behavior of the E-isomer of 2 is not clearly observed because of the low population under the conditions.
17. It is assumed that the nitrogen atom in Z-2 is pyramidal also in solution, though no experimental verification for it is available at present.