Microwave-assisted C–C bond forming cross-coupling reactions: an overview

Abstract

Among the fundamental transformations in the field of synthetic organic chemistry, transition-metal-catalyzed reactions provide some of the most attractive methodologies for the formation of C-C and C-heteroatom bonds. As a result, the application of these reactions has increased tremendously during the past decades and cross-coupling reactions became a standard tool for synthetic organic chemists. Furthermore, a tremendous upsurge in the development of new catalysts and ligands, as well as an increased understanding of the mechanisms, has contributed substantially to recent advances in the field. Traditionally, organic reactions are carried out by conductive heating with an external heat source (for example, an oil bath). However, the application of microwave irradiation is a steadily gaining field as an alternative heating mode since its dawn at the end of the last century. This tutorial review focuses on some of the recent developments in the field of cross-coupling reactions assisted by microwave irradiation.

A helicopter view of microwave application to chemical processes: reactions, separations, and equipment concepts

“…The literature concerning the enhancement effects of microwaves on chemical reactions in general and homogeneous liquid-phase organic reactions, in particular, is exceptionally rich, and there exist several good reviews on this subject (Lidstrom et al 2001, Hajek 2002, Hayes 2002, Larhed et al 2002, Kappe 2004, Leadbeater et al 2004, Nuchter et al 2004, Dallinger and Kappe 2007, Kappe and Dallinger 2009, Kappe and Van der Eycken 2010, Bag et al 2011, Mehtaa and Van der Eycken 2011, McBurney et al 2012, Gupta et al 2013, Kranjc and Kocevar 2013a. The authors generally agree about the ability of microwave heating to accelerate the organic reactions and acceleration factors from several to more than 1000 are reported.…”

Microwave‐Heated Transition Metal‐Catalyzed Coupling Reactions

“…In this study, the palladium-catalyzed aminocarbonylation of aryl iodides and bromides was performed using Mo(CO) 6 as the CO-releasing reagent under microwave irradiation (Scheme 15.113). Among the metal carbonyls screened [Fe(CO) 5 , Cr(CO) 6 , and Co 2 (CO) 8 ], Mo(CO) 6 was found to be superior as a CO-releasing agent. Simple Pd/C was used as the catalyst for 4-substituted aryl iodides, whereas the carbonylation of aryl bromides required a more sophisticated catalytic system comprised of Herrmann's palladacycle {trans-di(µ-acetate)bis[o-(di-o-tolylphosphino)benzyl]dipalladium} [238] and rac-BINAP [2,2 -bis(diphenylphosphino)-1,1 -binaphthyl].…”

“…When the first edition of Microwaves in Organic Synthesis was compiled in 2002, it was possible to nurse the ambition to cover all aspects of the literature on microwave-heated homogeneous transition metal-catalyzed reactions within the scope of a book chapter [1]. Today, this is not easily done as the number of publications has increased significantly together with the range of investigated transformations [2][3][4][5][6][7][8]. The safety and reproducibility of microwave-heated chemistry are also better as most papers nowadays use dedicated single-or multimode equipment that are safe to use and generally show good inter-laboratory reproducibility [9].…”

The Beneficial Sinergy of MW Irradiation and Ionic Liquids in Catalysis of Organic Reactions

“…Reactions catalyzed by transition metals (in primis palladium) that lead to C-C bond formation are of the utmost importance in organic synthesis and it is not surprising that the problem to make them more sustainable received attention, considering in particular the use of microwave activation [59]. Palladium-catalyzed alkoxycarbonylation reaction was recently reviewed considering, among improvements, the use of alternative solvents (ILs, scCO2) and MW heating [60].…”