Selectivity versus reactivity -: Recent advances in RuO4-catalyzed oxidations

Since its introduction into organic chemistry more than fifty years ago, RuO4 has been used mainly as a strong oxidizing agent. Owing to its high reactivity, catalytic reactions employing RuO4 were often considered to be sluggish or unselective. However, within the past ten years, several groups have reported the development of new and selective oxidative transformations possible only under RUO4 catalysis. The present article summarizes the state of research in this field and tries to give a systematic overview of the reactivity and the reaction mode of RuO4. In the final section, relative reactivities between olefins or olefins and functional groups are discussed. The information provided in the present paper might serve as a good starting point for chemists interested in applying RuO4- catalyzed reactions in organic synthesis or methodology. 1 Introduction 1.1 Historical Development 1.2 Chemical Properties 2 Oxidation of C-H Bonds 2.1 Oxidation of C-H Bonds a to a Heteroatom 2.2 Oxidation of Saturated Hydrocarbons 3 Oxygen Transfer to Alkenes 3.1 Dihydroxylation and Ketohydroxylation 3.2 Oxidative Cyclization of Polyenes 4 Cleavage Reactions 4.1 Oxidative Cleavage of Single Bonds 4.2 Oxidative Cleavage of Double Bonds 4.2.1 Fragmentation of Alkenes 4.2.2 Oxidation of Aromatic Compounds 4.3 Oxygen Transfer to Alkynes 5 Oxidation of Heteroatoms 6 Reactivity Aspects 7 Conclusions.