Hiyama cross-coupling reactions

Name Reactions A Collection of Detailed Mechanisms and Synthetic Applications, DOI 10.1007/978-3-319-03979-4 134, Springer International Publishing Switzerland 2014 

Hiyania, T. In Metal-Catalyzed Cross-Coupling Reactions 1998, Diederich, F. Stang, P. J., Eds. Wiley-VCH Weinheim, Germany, pp 421-53. (Review). 

Benito-Garagorri, D. Mereiter, K. Froehlich, J. Kirchner, K. Organome-tallics 2005,24, 3957-3965. 

Hiyama Cross-Coupling Reaction. In Name Reactions for Homologations-Part / Li, J. J., Ed. Wiley Hoboken, NJ, 2009, pp 33-416. (Review). 

Name Reactions, 4th ed., DOI 10.1007/978-3-642-01053-8 126, Springer-Verlag Berlin Heidelberg 2009 

The palladium-catalyzed reaction of alkenyl-, aryl-, alkynyl- and alkylsiloxanes with aryl, alkyl, and alkenyl halides and triflates in the presence of activators is known as the Hiyama cross-coupling reaction and several reviews have been published. This chapter will present major developments and examples of recent carbon-carbon bond formation methodology and improvements as well as their use in natural products synthesis in the last few years. 

Hiyama then wondered what would happen if a palladium complex was present in the reaction mixture. The questions he asked, Does a 

The most commonly accepted mechanism for this coupling was initially proposed by Hiyama and Hatanaka, which involves three steps.The first step is the oxidative addition of the aryl halide to the palladium(O) catalyst to give arylpalladium complex 1. The second step involves the transmetallation of the arylpalladium complex 1 with the anionic arylsilicate 2 to give bis(aryl)palladium complex 3. Finally, the cross-coupled product 4 is produced and the palladium(O) catalyst is regenerated through reductive elimination of the bis(aryl)palladium(II) complex 3. The key intermediate to this process is the requirement for the pentacoordinate arylsilicate anion 2, typically formed by treatment of the tetracoordinate silane with the activating anion, such as tetrabutylammonium fluoride (TBAF). 

To overcome the limitations of using TBAF as an activating reagent in sensitive compounds containing silicon protecting groups, Denmark 

Several reviews have shown variations and improvements in the scope and 

R = alkenyl, aryl, alkynyl, alkyl R = aryl, alkyl, alkenyl Y = (0R)3, Me3, Me20H, Mep jF(n+3j X = Cl, Br, I, OTf activator = TBAF, base 

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Fluoride-free Hiyama cross-coupling reactions of phenyltrimethoxysilane with aryl halides was performed in water using sodium hydroxide as activator at 110°C under microwave heating [32]. The reaction was catalyzed by poly (N-viityl-2-pyrrolidone) (PVP)-stabilized colloidal palladium NPs. The reaction proceeds quickly under microwave heating (6 min). 

Shah D, Kaur H (2013) Microwave assisted fluoride-free Hiyama cross-coupling reaction catalyzed by Pd(0)-PVP nanoparticles. Curr Catal 3(1) 39 6. doi l0.2174/2211544711302 9990016... 

A colloidal palladium nanoparticle prepared from a Fischer carbene complex of tungsten with K2PdCl4 as the reductant and PEG as the capping agent, efficiently catalyzed the Hiyama cross-coupling reactions in air. ... 

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