Pouilhes, A.
Langlois, Y.
Nshimyumukiza, Prosper
[UCL]
Mbiya, K.
Ghosez, Léon
[UCL]
Trimethylsilyl triflate and t-butyldimethylsilyl triflate can be used as activating reagents in the cycloaddition between chiral oxazoline 1 and cyclopentadiene. However, better results were obtained with a mixture of trifluoroacetic anhydride and trimethylsilyl triflate which gave rise to highly stereoselective cycloaddition. Oxazoline 1 and siloxy-2-azadienes 7, 8, 9 and 10 afforded, in the presence of trimethylsilyl triflate, cycloadducts 11, 12, 13 and 14. Endo adducts were obtained with open chain dienes, whereas exo adducts were the major products with the cyclic diene 10. The diastereoselectivity was highly dependent upon the structure of the diene.
Bibliographic reference |
Pouilhes, A. ; Langlois, Y. ; Nshimyumukiza, Prosper ; Mbiya, K. ; Ghosez, Léon. Asymmetric Diels-alder Cycloadditions of Alpha,Beta-unsaturated Oxazoline To 2-azadienes. In: Societe Chimique de France. Bulletin, Vol. 130, no. 3, p. 304-309 (1993) |
Permanent URL |
http://hdl.handle.net/2078.1/49615 |