Sigmatropic rearrangements of 'onium' ylids

Sweeney, J.B. (2009) Sigmatropic rearrangements of 'onium' ylids. Chemical Society Reviews, 38 (4). pp. 1027-1038. ISSN 0306-0012 doi: 10.1039/b604828p

Abstract/Summary

Rearrangement reactions occupy a special place within the canon of organic synthesis, by virtue of the inherently high efficiency of chemical processes which form and breyak bonds by redistribution of electrons around a retained atomic framework. Within the broader class, sigmatropic rearrangements are chemical processes defined by mechanisms involving unimolecular migration of sigma-bonds with concomitant redistribution of one or more pi-bonds. Sigmatropic processes may involve uncharged or charged species, with the charges located on carbon or heteroatoms; the latter reaction type is the subject of this tutorial review.