Chapter 4. Sonogashira Coupling

The Sonogashira reaction has become a powerful method for the preparation of C(sp2)–C(sp) conjugated bonds. The ability to couple arenes and alkenes to alkynes allows for the chemoselective introduction of unsaturation into molecules under mild conditions. More often than not, this unsaturation is then further elaborated into the requisite target molecule. The mildness of the method also means that alkynes can be introduced late in a synthetic sequence when required in the final product. This chapter details various mechanistic aspects of the reaction as well as a number of industrially relevant examples, several of which have been performed on a development scale. The recent introduction of more active catalytic systems has enabled a broader substrate scope and lower catalyst loadings, facilitating the development of greener and more cost efficient synthetic routes.