Barry Sharpless called one of these reactions, which reacts azides and alkynes,"the premier example of a click reaction.
It's not related to the Wittig reaction, but a reaction with this mechanism reacts ketenes with imines and is known as the Staudinger synthesis. The thymine dimerization that causes sunburns forms from this kind of reaction mechanism. Transition states in these reactions can adopt topologies named for Mobius and Huckel. Molecular orbitals of reactants must flow smoothly into molecular orbitals of products according to the conservation of (*) orbital symmetry which was used to develop the Woodward-Hoffman rules. Barry Sharpless called one of these reactions, which reacts azides and alkynes,"the premier example of a click reaction." These reactions include the Huisgen reaction as well as a reaction between a diene and a dienophile in a [4 + 2] fashion. For 10 points name this class of pericyclic ring forming reactions which includes the Diels-Alder reaction.
It's not related to the Wittig reaction, but a reaction with this mechanism reacts ketenes with imines and is known as the Staudinger synthesis.
cycloaddition reaction [ prompt on pericyclic reaction and ring-forming reaction before read; prompt on addition]