Pd/C Catalysis under Microwave Dielectric Heating

Abstract

Microwave-assisted organic synthesis (MAOS) provides a novel and efficient means of achieving heat organic reactions. Nevertheless, the potential arcing phenomena via microwave (MW) interaction with solid metal catalysts has limited its use by organic chemists. As arcing phenomena are now better understood, new applications of Pd/C-catalyzed reactions under MW dielectric heating are now possible. In this review, the state of the art, benefits, and challenges of coupling MW heating with heterogeneous Pd/C catalysis are discussed to inform organic chemists about their use with one of the most popular heterogeneous catalysts.

The Current Status of Heterogeneous Palladium Catalysed Heck and Suzuki Cross-Coupling Reactions

“…Palladium supported on carbonaceous supports has been widely applied in C–C cross-coupling reactions ( Scheme 2 ) [ 16 , 17 , 18 ]. Amongst these, palladium on activated carbon (Pd/C) is by far the most frequently used catalyst in heterogeneous Pd-catalyzed coupling reactions.…”

“…Amongst these, palladium on activated carbon (Pd/C) is by far the most frequently used catalyst in heterogeneous Pd-catalyzed coupling reactions. This is because of its efficiency and commercial availability [ 16 , 17 , 18 ]. It can be purchased in various quantities with a palladium content ranging from 1–20%.…”

Heck Reaction—State of the Art

“…Recently, the state of the art, benefits, and challenges of coupling microwave heating with heterogeneous Pd/C catalysis are discussed in the review by Cini et al [29]. Microwave dielectric heating allowed a significant acceleration of the C-C coupling reaction rate, shortening the reaction time from hours to minutes.…”

Development of the Applications of Palladium on Charcoal in Organic Synthesis

“…Additional future applications of Pd/C are expected to focus on sustainable chemistry development, because this research area remains a fateful domain for the progress of synthesis and process understanding. Thus, it is consequently expected that organic chemists will provide even more attention to Pd/C or other heterogeneous Pd catalysis systems particularly in water, in order to satisfy the demand for more eco‐compatible procedures. This approach would obviously greatly contribute to establish ‘green chemistry’.…”