3.1 Heck Reactions

AbstractThe arylation of terminal alkenes bearing mesomerically electron-withdrawing groups is the archetypal palladium(0)-catalyzed Heck reaction, also known as the Mizoroki–Heck reaction. These substrates generally provide a very high regioselectivity, with both steric and electronic factors favoring arylation at the terminal position of the alkene. Additionally, diastereoselectivity is generally very high, and products with an E configuration are obtained exclusively in most cases. In the wake of the pioneering studies on this reaction in which stoichiometric amounts of palladium reagents were used, iodoarenes were introduced as arylating agents in a catalytic version of the reaction; these were later supplemented by bromo- and chloroarenes. Subsequently, many other arylating agents, such as pseudohalides, aroyl chlorides, and diazonium or iodonium salts, have been introduced as electrophiles in the Mizoroki–Heck reaction. Later advances include the development of oxidative Heck arylations catalyzed by palladium(II) species.This chapter aims to provide a general perspective on the applicability of this type of coupling chemistry, and to describe the depth and breadth of various aspects that have been researched and refined in making the Heck reaction of alkenes bearing electron-withdrawing groups a cornerstone of the art of C—C bond formation.