Diene tricarbonyl iron complexes bearing a free diazo group. III. Synthesis of pyrazoles and chiral complexes with α-aminoacid or dienylcyclopropane substructures by 1,3-dipolar cycloaddition reactions

Tetrahedron Letters

Volumn 39, Issue 31, 1998, Pages 5643-5646

  Franck Neumann, Michel ^a   Geoffroy, Philippe ^a   Winling, Alain ^a  

^a UNIVERSITÉ DE STRASBOURG   (France)

Author keywords

[No Author keywords available]

Indexed keywords

ALPHA AMINO ACID; DIENYLCYCLOPROPANE DERIVATIVE; PYRAZOLE DERIVATIVE; UNCLASSIFIED DRUG;

ARTICLE; CHEMICAL STRUCTURE; CHIRALITY; CYCLIZATION; DIASTEREOISOMER; SYNTHESIS;

EID: 0032581752     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(98)01097-1     Document Type: Article

References (17)

1. 1. Franck-Neumann, M.; Geoffroy, P.; Winling, A. Tetrahedron Lett., 1995, 36, 8213.
2. 2. Franck-Neumann, M.; Geoffroy, P.; Winling, A. Synlett, 1995, 341.
3. 3. Similarly to 1, the diazoketone 2 was obtained in 30 % yield by treatment of the acid chloride of complexed sorbic acid with diazoethane (10 eq., ether, 0° C).
4. 4. Franck-Neumann, M.; Buchecker, C. Tetrahedron Lett., 1972, 937. Franck-Neumann, M.; Buchecker, C. Angew. Chem., 1973, 85, 259.
5. 4. Franck-Neumann, M.; Buchecker, C. Tetrahedron Lett., 1972, 937. Franck-Neumann, M.; Buchecker, C. Angew. Chem., 1973, 85, 259.
6. 5. Franck-Neumann, M.; Dietrich-Buchecker, C. Tetrahedron Lett., 1976, 2069.
7. 2, only a methoxycarbonyl group is cleaved. The structure of the main transposition product 6 was secured by X-ray diffraction, the details of which will be given in the full paper. (formula presented)
8. 3, 200 MHz, ppm/TMS, J) : δ = 1.48 (d, 3H, 6.2 Hz), 1.70 (m, 1H), 2.25 (d, 1H, 8.5 Hz), 3.15 (dd, 1H, 17.7 and 11.8Hz), 3.25 (dd, 1H, 17.7 and 6.1 Hz), 3.75 (s, 3H), 4.45 (dd, 1H, 11.8 and 6.1), 5.26 (m, 1H), 5.86 (dd, 1H, 8.5 and 5.0 Hz), 6.66 (s, 1H).
9. 2, c = 0.7).
10. 2Et).
11. 3, 200 MHz, ppm/TMS, J) : δ = 1.11 (d, 1H, 9.8Hz), 1.12(m, 1H), 1.25 (t, 3H, 7.1 Hz), 1.38 (d, 3H, 6.2 Hz), 1.46 (dd, 1H, 7.1 and 4.8Hz), 2.07 (dd, 1H, 8.8 and 4.8 Hz), 2.33 (dd, 1H, 8.8 and 7.1 Hz), 3.67 (s, 3H), 4.11 (m, 2H), 4.98 (dd, 1H, 8.8 and 5.2 Hz), 6.12 (dd, 1H, 9.5 and 5.2 Hz).
12. 1-pyrazolines, since evolution of nitrogen is unexpected at such low temparetures with two symmetrically distributed electron with-drawing substituents. This originates probably from the stabilization of the intermediate radicals by a capto-dative effect.
13. 12. The thermolysis was performed at 30° C for 24 h instead of 70° C for 3 h for the racemic complex. This explains the differences in yields observed and the better overall yield, since at 30° C only traces of monomolecular decomposition products are observed.
14. 13. cf. Franck-Neumann, M.; Bissinger, P.; Geoffroy, P. Tetrahedron Lett., 1997, 38, 4473.
15. 14. Van Alphen, J. Rec. Trav. Chim. Pays-Bas, 1943, 62, 485 and 491. Hüttel, R.; Franke, K.; Martin, H.; Riedl, J. Chem. Ber., 1960, 93, 1433.
16. 14. Van Alphen, J. Rec. Trav. Chim. Pays-Bas, 1943, 62, 485 and 491. Hüttel, R.; Franke, K.; Martin, H.; Riedl, J. Chem. Ber., 1960, 93, 1433.
17. 15. Franck-Neumann, M.; Briswalter, C.; Chemla, P.; Martina, D. Synlett, 1990, 637.