Heck reaction overview

For overviews of applications of the Heck reaction in natural products synthesis, see (a) Link, J. T. Overman, L. E. In Metal-Catalyzed Cross-Coupling Reactions, Diederich, F., Stang, P. J., Eds. Wiley-VCH New York, 1998 Chapter 6. (b) Brase, S. de Meijere, A. In Metal-Catalyzed Cross-Coupling Reactions Diederich, F., Stang, P. J., Eds. Wiley New York, 1998 Chapter 3.6. (c) Nicolaou, K. C. Sorensen, E. J. Classics in Total Synthesis VCH New York, 1996 Chapter 31. These authors refer to the Heck reaction as "one of the true "power tools" of contemporary organic synthesis" (p. 566). 

The term Heck reaction is associated with such a huge variety of transformations that it is impossible to cover them all within the scope of this chapter. We therefore restricted ourselves to giving an outline of the reaction principle and discussing a number of illustrative developments in this exciting field of research. For a more comprehensive overview, we recommend recent review articles [6-8],... 

Comprehensive overviews of the current state of mechanistic theory regarding the Heck reaction have been provided in two recent review articles [5,12]. In the following the discussion will be a selective one, focusing primarily on the factors which impart the regio- and enantiocontrol necessary for a successful AHR [13,14]. 

Non-conventional methodologies for transition-metal catalysed carbon-oarbon coupling A critical overview. Part 1 The Heck reaction Alonso, F. Beletskaya, I.P. Yus, M. Tetrahedron 2005, 6/, 11771. 

Alonso, R, Beletskaya, I.R and Yus, M. (2005) Non-conventional methodologies for transition-metal catalyzed carbon—carbon coupling a critical overview. Part 1 the Heck reaction. Tetrahedron, 61, 11771-835. 

Overview of Chelation-Controlled Mizoroki-Heck Reactions... 

For recent reviews on the Mizoroki-Heck reaction, see (a) Alonso, F., Beletskaya, I.P. and Yus, M. (2005) Non-conventional methodologies for transition-metal catalysed carbon-carbon coupling a critical overview. Parti theHeckie ction.Tetrahedron,61,11771-835 (b) Erase, S. and de Meijere, A. (2004) Cross-couphng of organyl halides with alkenes the Heck reaction, in... 

The common feature of Mizoroki-Heck reactions is the palladium(O)-catalysed arylation or alkenylation of alkenes [1]. During recent years, several excellent overviews about this topic have been published [7-12]. The reaction is usually carried out under basic conditions. Stoichiometric amounts of base are needed to neutralize the acid which is formed during the reaction. 

The application of microwaves in Mizoroki-Heck reactions is well documented. There are several overviews of this topic [12, 200-204]. During the last year, new trends in the Mizoroki-Heck reaction conducted under microwave irradiation are the application of solid-supported catalysts and the combination with other activation methods for example,... 

In 1972, Heck showed, independently, that aryl, benzyl and styryl halides would react with alkenes in the presence of a hindered amine as organic base at a lower reachon temperature of 100 °C (Scheme 1.16) [51, 66]. A detailed overview on the modem aspects of Mizoroki-Heck reactions, as well as their oxidative variants (Fujiwara reactions), is provided by Martin Oestreich and Verena Trepohl in Chapter 7. 

Over the past 5 years the number of reports on the use of palladium-catalyzed reactions for solid-phase derivatizations has greatly increased. In this section (and throughout this chapter), we limit our scope to representative applications for the modification of solid-supported heterocyclic scaffolds. A more general overview of the versatility of Suzuki, Heck, and Stille reactions on solid supports was recently provided by Franzen.32... 

This review attempts to provide an overview of microwave-promoted metal-catalyzed transformations of aryl and vinyl halides (or pseudo halides), providing a personal selection of both pioneering and very recently published work. Covered areas include carbonylative transformations, Heck and Sono-gashira reactions, nucleophilic substitutions and cross-couplings. Because of the diversity of the microwave systems used, the reader should consult the original references for detailed descriptions of settings and instrumentation. 

As indicated in the previous example, carbopalladation does not necessarily culminate in /i-hydride elimination as the expected outcome of reactions under Heck conditions. In those cases where the initial carbopalladation can be reversed at a later stage in the sequence fascinating options for catalytic processes may evolve. In particular, Catellani (for an overview see [67]) has established that norbornene, a strained olefin, which is reversibly introduced and eliminated, might efficiently serve as a relay to open new pathways for Pd-mediated processes. Indeed, most of the processes were explored and conducted both in a stoichiometric and in a catalytic fashion. 

Heck s 1985 book gives an overview of the non-asymmetric reaction. Heck RF (1985) Palladium Reagents in Organic Synthesis. Academic Press, London... 

Table 1 gives an overview of addition reactions to unsaturated compounds. C-C coupling reactions such as Heck, Suzuki and Sonogashira coupling are described in Section 7.4.2. 

This section gives a concise overview on the construction of heterocycles by Heck-type reactions all reactions covered here mechanistically start with an oxidative addition of a C-haUde or another appropriate C-heteroatom bond to a Pd(0) species and go on either with a carbopalladation step (intramolecular in Sect. B and intermolecular in Sect. C) or a cyclopalladation step (Sect. D). The examples presented in the subsections are organized according to types of starting materials, since certain substructures turned out to be typical. 

The synthesis of heterocycles making use of Heck-type reactions is obviously a growing field of current research, which takes advantage both of the broad applicability of palladium catalysis and of the outstanding importance of heterocycles. Palladium catalysis is even more useful for heterocyclic chemistry when taking into account that the Pd-catalyzed de-rivatization of heterocycles is not included in this overview. 

SCHEME 23 Overview of the Heck-Matsuda reaction with cyclic olefins. Asterisk in compound 111 indicates the presence of a stereogenic center of unknown absolute configuration. 

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