Pd Metal Catalysts for Cross-Couplings and Related Reactions in the 21st Century: A Critical Review

Abstract

Cross-couplings and related reactions are a class of highly efficient synthetic protocols that are generally promoted by molecular Pd species as catalysts. However, catalysts based on more or less highly dispersed Pd metal have been also employed for this purpose, and their use, which was largely limited to the Heck reaction until the turn of the century, has been extended in recent years to most reactions of this class. This review provides a critical overview on these recent applications of Pd metal catalysts. Particular attention is devoted to the discussion of the mechanistic pathways that have been proposed to explain the catalytic role of Pd metal. Furthermore, the most outstanding Pd metal based catalytic systems that have emerged are illustrated, together with the development of novel approaches to boost the reactivity of Pd metal. A section summarizing the current industrial applications of Pd metal catalyzed reactions of this kind concludes the review.

Palladium on magnetic Irish moss: A new nano‐biocatalyst for suzuki type cross‐coupling reactions

“…However, these ligands are usually expensive, toxic and not readily separable . Therefore, the development of highly active heterogeneous ligandless catalysts has attracted considerable attention in recent years …”

Synthesis, characterization and catalytic performance of palladium supported on pyridine‐based covalent organic polymer for Suzuki‐Miyaura reaction

“…Among the catalytic reactions discovered in the last century, the palladium‐catalyzed Suzuki‐Miyaura cross‐coupling reaction constitutes the most well‐known and the widely used method for carbon–carbon bond construction method on a laboratory and industrial scale . Despite many successes have been achieved, unfortunately, many of these reactions use phosphine ligands or toxic organic solvents in a homogeneous process.…”

Synthesis of Pyridazine Derivatives by Suzuki-Miyaura Cross-Coupling Reaction and Evaluation of Their Optical and Electronic Properties through Experimental and Theoretical Studies

“…that are commercially available, it occurs under mild reaction conditions, it is largely unaffected by the presence of water, it tolerates a wide variety of functional groups, it generally proceeds regio- and stereoselectively, while the inorganic by-products are non-toxic and easily removed from the reaction mixture. All of these qualities contribute to make the Suzuki coupling suitable not only for laboratories, but also for myriad industrial processes [1,2,3,4,5,6,7]. …”