Dioxirane-Based Stereoselective and Oxidative Transformations

The synthesis of chiral organic molecules is a purity-driven research that has become an essential part of our lives due to their applications in pharmaceuticals. Contemporary research focuses on the exploration of synthetic protocols that obviate the use/generation of hazardous chemicals. In this regard, dioxiranes are readily accessed as a reagent solution or catalyst (in situ) from the reaction of ketone with a co-oxidant like Oxone (R) or H2O2; the latter makes the protocol very green and inexpensive. It has shown the potential to replace transition metal-based oxygenation protocols. The dioxirane-mediated asymmetric reactions include oxidations, epoxidations, C-H hydroxylations, etc. Both stoichiometric and catalytic protocols of dioxiranes are been explored for the oxyfunctionalization of chiral natural product derivatives such as Penicillin, nucleosides, amino acids, carbohydrates, etc. In addition, these are employed as key oxygenation agents during the synthesis of natural products like (+)-Plagiogyrin A, Portimine, Taxol, Bryostatin, dafachronic acid, majucinoids, eldecalcitol, Spirochensilide A, etc. The review consolidates the development of both achiral and chiral dioxiranes in application to asymmetric synthesis and oxygenation of chiral molecules. The dioxirane-based asymmetric oxidation protocols are mild, inexpensive and eco-friendly. Several asymmetric oxidations, for example, epoxidation, C-H hydroxylation, alcohol/sulfide/amine oxidations, etc., can be performed using dioxiranes. Therefore, dioxiranes are very useful and are important components present in the arsenal of organic chemists for the synthesis of biologically relevant drugs and natural products. image