Reactions of O,O'-disubstituted benzonitrile oxides with 8-azaheptafulvenes

Article abstract of DOI:10.3987/com-97-s(n)76

In the reaction of O,O′-disubstituted benzonitrile oxides (If-h) with 8-p-tolyl-8-azaheptafulvene (2) in cyclohexane there is a competition between attack by the nitrile oxides on the C=N moiety [to give a mixture of equilibrating "fused" and "spiro" adducts (3/4)] and on the C₂-C₃ double bond (to give 12 which isomerizes to 13) of 2. Site selectivity was highly enhanced by carrying out the reaction in polar solvents. Only the attack on the C=N moiety was observed in the polar and protic methanol. A synthesis of 13 by a mild new procedure of decomplexation of the tricarbonyliron complex of 12 (i.e., 15) is described.