Sequential Addition/Elimination Reactions
In this chapter, the authors look at the sequential addition/elimination reactions that result in an overall substitution occurring on the original substrate. Many of the reactions have intermediates that are both neutral and possess a full complement of electrons, that is, they are neither radical nor carbene intermediates. Some of these intermediates may be isolated; however, many are very reactive and so may only be produced in situ. However, the order of the reactions may be reversed, that is, an elimination reaction followed by an addition reaction will also have the same result. The alkane and alkene intermediates have been isolated, which supports the contention that an addition/elimination sequence has been followed. After the first addition, which yields the saturated compound, two elimination reactions occur to give the alkyne derivative. This then undergoes a second addition to result in the final, rearranged, substitution product.