Organoselenium Compounds in Catalysis

Abstract In this article we have focused on the use of selenium in catalysis along with the proposed reaction mechanisms. With increasing interest in selenium chemistry, we have highlighted the most significant features of this subject, mainly in the last years. Selenium-containing catalysts have a key role in many transformations; for example, oxidation reactions that are performed under very mild and controlled conditions. In addition, utilizing the weak selenium–oxygen bonding interaction has proved to be very useful as a catalytic approach for specific transformations. The catalytic cycles of each appropriate transformation are fully reviewed. 1 Introduction 2 Use of Selenium in Catalysis: Perspectives 2.1 Selenium as Directing Group: Preparation of Organoselenium Compounds via C–H Borylation 2.2 Multicomponent Reactions Employing Selenium as a Catalyst 2.3 Selenium-π-Acid Catalysts 2.4 Electrochemical Selenium-Catalyzed Reactions 2.5 Stereoselective Synthesis Employing Organoselenium Catalysts 2.6 Transition-Metal Catalysts Containing Selenium-Based Ligands 2.6.1 Selenium-Ligated Palladium(II) Complexes as Catalysts for the Heck Reaction 2.6.2 Pincer Selenium Catalyst for the Allylation of Aldehydes and Closely Related Functional Groups 2.6.3 Selenium Employed in Buchwald-Type C–N Coupling Reactions 2.6.4 Organoselenium Catalysts in Suzuki–Miyaura Coupling Reactions 2.7 Organoselenium Catalysis in Michael-Type Reactions 2.8 Catalytic Cycle for Glutathione Peroxidase 2.9 Epoxidation 2.10 Dihydroxylation 2.11 Oxidation 2.12 Bromolactonization 2.13 Preparation of Alkenes from Vicinal Diols 2.14 Preparation of α-Selanyl Enals from Propargylic Alcohols 2.15 Miscellanea 3 Concluding Remarks