The first direct observation of an allylic [3,3] sigmatropic cyanate-isocyanate rearrangement

Evidence is presented that the [3,3] sigmatropic rearrangement of simple allyl cyanates to give allyl isocyanates proceeds much more rapidly than the analogous reaction of propargyl cyanates. Nevertheless, a substituted allyl cyanate is isolated for the first time, and the activation parameters of its [3,3] sigmatropic isomerization are measured. (C) 2001 Elsevier Science Ltd. All rights reserved.