This review covers the 1, 3-cycloaddition of benzonitrile oxides to dipolarophiles that contain both C=N (or C≡N) and C=C (or C≡C) bonds and in several cases it is the unsaturated carbon-nitrogen bond that is the preferred site of competitive attack. There are cases when there is no attack at the C=C bond, while in other cases attack does occur but it is accompanied by structural modifications, like the elimination of small molecules (NH3, H2, amines), closure to make a further ring or the opening of an existing one and, sometimes, further reaction of the primary product.
A small substituent effect was found when variously substituted benzonitrile oxides were considered. Thus, the choice of the aryl nitrile oxide is usually not critical for either the reaction products or the reaction rate.
Buy this Article