Proximity-assisted cycloaddition reactions--facile Lewis acid-mediated synthesis of diversely functionalized bicyclic tetrazoles.
Aliphatic azidonitriles separated by three or four carbon atoms undergo facile Lewis acid-induced cycloadditions to give bicyclic tetrazoles, even at 0 degrees C. Extension to 3-azido-2-aryl-1,3-dioxolanes and the corresponding 1,3-dioxanes in the presence of TMSCN and BF3.OEt2 leads to a series of diversely functionalized novel oxabicyclic tetrazoles. The reactions represent new aspects of proximity-assisted dipolar cycloadditions that afford thermodynamically controlled enantiopure products proceeding through discrete oxocarbenium ion intermediates.
Hanessian
Stephen
S
Department of Chemistry, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada. stephen.hanessian@umontreal.ca
Simard
Daniel
D
Deschênes-Simard
Benoît
B
Chenel
Caroline
C
Haak
Edgar
E