Introduction Dimethyldioxirane (DMD), a nonmetal organic oxidant, has the ability to transfer an oxygen atom to a wide range of substrates and functionalities, including C=C and C-H bonds in hydrocarbons as well as atoms containing lone pairs such as sulfide,
[1 ]
primary and secondary amines.
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This nonmetal electrophilic oxygen transfer agent is the reagent of choice for most epoxidation reactions (better than MCPBA) due to its substrate-induced selectivity, specificity, and reactivity under mild conditions (at 0-25 °C and neutral pH). It reacts rapidly and in high yield, is easy to handle and applicable to acid- or base-sensitive substrates, and it can be used to synthesize hydrolytically labile oxyfunctionalized products.
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DMD-mediated halogenations,
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hydroxylations,
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and oxidations are widely used in the chemistry of flavonoids, low-molecular-weight natural compounds and in expanding the organoborane chemistry.
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[b ]
It also acts as a G-specific chemical sequencing agent and is a new source of singlet oxygen generation.
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Preparation DMD is easily prepared by oxidizing acetone with commercially available low-cost potassium peroxymonosulfate KHSO5 (Oxone, Caroate) in water buffered at pH 7-7.5 using NaHCO3 (Scheme
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). It is obtained as yellow solution in acetone in the range of 0.07-0.09 M concentration and usually stored in the freezer (-25 °C).
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Scheme 1