Cooperation between p-Block Elements and Redox-Active Ligands: Stoichiometric and Catalytic Transformations

The relevance acquired by redox-active ligands in modern catalysis stems from their facile delivery and acceptance of electrons, either to the metal they coordinate to, or directly to an incoming substrate that also binds the central metal. Doing that, they generate coordinated radicals and provide access to more than one spin state during the catalytic cycle. As a consequence, the new reaction barriers are reduced when compared to similar processes that are restricted to a single spin surface. The principles that govern this genuine approach to catalyst design are well-established, and their implementation has allowed the development of synthetically useful catalytic transformations; however, the extension of the concept to species in which p-block elements take the role of central atoms remains largely underdeveloped. Through discussion of the key achievements and recent progress, this Concept Article highlights this original approach to designing (organo)catalysts, discloses the progress achieved, and also reveals the many shortcomings that still exist in the field. Ignoble prized: The use of redox-active ligands that behave as electron reservoirs and are able to donate or accept electrons on demand during a catalytic cycle has emerged as a powerful approach to engage cheap early transition metals in catalytic transformations traditionally reserved for their noble cousins. This concept article explores the possibilities that are opened by the extrapolation of that strategy to the design of catalysts based on p-block elements.image

Automated summary

The relevance of redox-active ligands in modern catalysis lies in their ability to easily deliver electrons and generate coordinated radicals, reducing reaction barriers and accessing multiple spin states. While this approach is well-established for metal central atoms, its application to p-block elements remains underdeveloped.