Recent advances in noble metal nanocatalysts for Suzuki and Heck cross-coupling reactions

Abstract

Since metal nanoparticles have a high surface-to-volume ratio and very active surface atoms, they are very attractive catalysts for a wide variety of organic and inorganic reactions, compared to bulk catalysts. Metal nanoparticles suspended in colloidal solutions and those adsorbed onto bulk supports have been used as catalysts for a wide variety of carbon-carbon bond formation reactions such as the Suzuki and Heck cross-coupling reactions. This review article highlights some of the latest advances in the application of noble metal nanoparticles as catalysts for these two industrially important classes of cross-coupling reactions. We will discuss several important advances in using metal nanocatalysts in Suzuki and Heck cross-coupling reactions such as investigations on the nanoparticle shape dependence on the catalytic activity, novel types of supported metal nanoparticles as nanocatalysts, and the use of bi-metallic, tri-metallic and multi-metallic nanoparticles as catalysts for the Suzuki and Heck cross-coupling reactions.

Scheme 1

Examples of some types of Suzuki and Heck cross-coupling reactions and the mechanism of the Suzuki reaction.

Figure 1

HRTEM image of a tetrahedral nanoparticle (a) and the transformed spherical platinum nanoparticle (b). Reprinted (“Adapted” or “in part”) from [39] with permission. © 2005 American Chemical Society.

Figure 2

Schematic of the seed-mediated growth process for synthesis of palladium nanorods and branched palladium nanostructures Reprinted (“adapted” or “in part”) with permission from [40]. © 2009 American Chemical Society.

Figure 3

TEM images of triangular and rectangular shaped palladium nanoparticles Reprinted from [41] with permission from Wiley-VCH Verlag GmbH and Co., © 2009.

Figure 4

TEM image showing the palladium nanoparticles adsorbed onto the magnetic nanoparticles (a) and HRTEM image showing the lattice fringes of the palladium nanoparticles as well as the electron diffraction pattern observed (b) Reprinted from [43] with permission from Elsevier, © 2009.

Figure 5

TEM image of the Pd-DMAP nanoparticles bound to MWCNTs (a) Size distribution of the palladium nanoparticles bond to the MWCNTs (b). Reprinted from [44] with permission from Elsevier, © 2009.

Figure 6

TEM image and EDS spectra for the Pd-Ag bimetallic nanoparticles supported on ZnO Reprinted from [53] with permission from Hindawi Publishing Corporation, © 2009.

Figure 7

Experimental schematic of the different combinations of monometallic, bimetallic, tri-metallic and multi-metallic nanoparticles synthesized. Reprinted (“adapted” or “in part”) with permission from [38], © 2002 American Chemical Society.