Abstract
In the last years ruthenium tetroxide is increasingly being used in organic synthesis. Thanks to the fine tuning of the reaction conditions, including pH control of the medium and the use of a wider range of co-oxidants, this species has proven to be a reagent able to catalyse useful synthetic transformations which are either a valuable alternative to established methods or even, in some cases, the method of choice. Protocols for oxidation of hydrocarbons, oxidative cleavage of C–C double bonds, even stopping the process at the aldehyde stage, oxidative cleavage of terminal and internal alkynes, oxidation of alcohols to carboxylic acids, dihydroxylation of alkenes, oxidative degradation of phenyl and other heteroaromatic nuclei, oxidative cyclization of dienes, have now reached a good level of improvement and are more and more included into complex synthetic sequences. The perruthenate ion is a ruthenium (VII) oxo-species. Since its introduction in the mid-eighties, tetrapropylammonium perruthenate (TPAP) has reached a great popularity among organic chemists and it is mostly employed in catalytic amounts in conjunction with N-methylmorpholine N-oxide (NMO) for the mild oxidation of primary and secondary alcohols to carbonyl compounds. Its use in the oxidation of other functionalities is known and recently, its utility in new synthetic transformations has been demonstrated. New processes, synthetic applications, theoretical studies and unusual transformations, published in the last eight years (2006–2013), in the chemistry of these two oxo-species, will be covered in this review with the aim of offering a clear picture of their reactivity. When appropriate, related oxidative transformations mediated by other metal oxo-species will be presented to highlight similarities and differences. An historical overview of some aspects of the ruthenium tetroxide chemistry will be presented as well.
Highlights
Oxidation is one of the fundamental reactions in synthetic organic chemistry both in academia and industry and there is always demand for selective and mild oxidation methods
Ruthenium tetroxide chemistry has further been developed in the last years
Most of the protecting groups used in organic synthesis are tolerant to the employed reaction conditions and stereogenic centres, even adjacent to the reacting functional group, are generally unaffected
Summary
Oxidation is one of the fundamental reactions in synthetic organic chemistry both in academia and industry and there is always demand for selective and mild oxidation methods. Numerous research groups have directed their efforts towards the development of novel oxidation processes and the trend is relentless. Significant progress has been achieved within the area of catalytic oxidations. In this regard transition metal oxo-species such as OsO4 [1,2], RuO4, RuO4−, MnO4− [3,4,5], rhenium [6,7] and references therein] and chromium oxo-species [8], play a primary role since they catalyze a wide spectrum of synthetically useful oxidative transformations [9,10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
