Effects of substituents on silicon upon the ring inversion of silepins annelated with bicyclo[2.2.2]octene frameworks

Chemistry Letters

Volumn , Issue 3, 1998, Pages 269-270

  Nishinaga, Tohru ^a   Izukawa, Yoshiteru ^a   Komatsu, Koichi ^a  

^a KYOTO UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0032349148     PISSN: 03667022     EISSN: None     Source Type: Journal    
DOI: 10.1246/cl.1998.269     Document Type: Article

References (13)

1. Y. Nakadaira, R. Sato, and H. Sakurai, Organometallics, 10, 435 (1991) and references cited therein.
2. T. Nishinaga, K. Komatsu, and N. Sugita, J. Org. Chem., 60, 1309 (1995).
3. 6) δ 3.10 (s, 2H), 2.77 (s, 2H), 2.69 (s, 2H), 1.1-1.5 (m, 24H).
4. w=0.050).
5. MOPAC 93.
6. For a review of this concept, see W. A. Bingel and W. Lüttke, Angew. Chem., Int. Ed. Engl., 20, 899 (1981).
7. S. Aonuma, K. Komatsu, and K. Takeuchi, Chem. Lett., 1989, 2107.
8. The tris(bicyclo[2.2.2]octeno)tropylium ion is the most stable tropylium ion ever known: K. Komatsu, H. Akamatsu, Y. Jinbu, and K. Okamoto, J. Am. Chem. Soc., 110, 633 (1988).
9. B. Goldfuss. P. v. R. Schleyer, and F, Hampel, Organometallics, 15, 1755(1996).
10. We assume that the electronic effect of substituents upon the C-Si-C angle is similar in both the boat and planar forms, and can mostly be canceled out: for example, the angle calculated for the planar form of 4e (115.3°) is larger than that of 4b (111.9°) similarly to the case of the boat forms (see text).
11. P. v. R. Schleyer, C. Maerker, A. Dransfeld, H. Jiao, and N. J. R. v. E. Hommes, J. Am. Chem. Soc., 118, 6317 (1996).
12. T. Nishinaga, Y. Izukawa, and K. Komatsu, J. Phys. Org. Chem., in press.
13. The values of magnetic susceptibility exaltation (A/ppm cgs) were also calculated for the planar forms of 1a-d (CSGT/6-311+G** //B3LYP/6-31G*) to give the following results: 1a: 2.2. 1b; 4.2, 1c; -4.4, 1d: -5.2. For the calculation method of A, see B. Goldfuss, and P. v. R. Schleyer, Organometallics, 16, 1543 (1997).