CHAPTER 9: Modern Heck Reactions

This chapter is devoted to a discussion of modern Heck reactions – a manifold of related processes involving the carbopalladation (carbometallation) of double and triple bonds. The relationships among the different processes involved are discussed. However, special attention is also paid to the classical Mizoroki–Heck reactions. Two distinct realizations of Mizoroki–Heck reactions – the ligand-accelerated pathway and the phosphine-free pathway – are covered in detail, with particular attention to demonstrate the profound differences in the approaches for designing effective catalytic systems. New ideas in expanding the scope of Mizoroki–Heck reaction associated with non-standard leaving groups, especially arenediazonium salts, are presented. One intriguing and very useful feature of arenediazonium chemistry in Heck reactions is the possibility of realizing very mild and tolerant base-free reactions. The last part of the chapter is devoted to the oxidative Heck reaction, comprising a series of related processes such as the now rapidly developing Fujiwara–Moritani reaction, and other reactions distinguished by the nature of the electrofugic leaving groups.