Facile 1,3-diaza-Claisen rearrangements of tertiary allylic amines bearing an electron-deficient alkene.
Tertiary allylic amines with an electron-deficient alkene react with isocyanates and isothiocyanates to give highly substituted ureas and thioureas arising from formal 1,3-diaza-Claisen rearrangements. Isocyanates and isothiocyanates with strong electron-withdrawing groups are more reactive. Similarly, the data suggest that a stronger electron-withdrawing substituent on the alkene favors a faster reaction, but this may be offset by sterics in the cyclic transition state.
Aranha
Rachel M
RM
Department of Chemistry, University of Vermont, Burlington, Vermont 05405, USA.
Bowser
Amy M
AM
Madalengoitia
Jose S
JS