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Similar to sulfonium-based oxidation of alcohols to aldehydes reactions, the Kornblum oxidation creates an alkoxysulphonium ion, which, in the presence of a base, such as triethylamine (Et 3 N), undergoes an elimination reaction to form the aldehyde or ketone.
The sulfonium oxidations can be categorized into two groups: The methods discovered earliest rely on activated alcohols like alkyl tosylates (Kornblum oxidation) [2] or alkyl chloroformates (from reaction of alcohols with phosgene: Barton-Kornblum) [3] that react as electrophiles when treated with DMSO, liberating an oxygenated leaving group (e.g. OTs−).
The oxidation states are also maintained in articles of the elements (of course), and systematically in the table {{Infobox element/symbol-to-oxidation-state}}
Oxidation states are typically represented by integers which may be positive, zero, or negative. In some cases, the average oxidation state of an element is a fraction, such as 8 / 3 for iron in magnetite Fe 3 O 4 . The highest known oxidation state is reported to be +9, displayed by iridium in the tetroxoiridium(IX) cation (IrO + 4). [1]
Oxidation state is an important index to evaluate the charge distribution within molecules. [2] The most common definition of oxidation state was established by IUPAC, [3] which let the atom with higher electronegativity takes all the bonding electrons and calculated the difference between the number of electrons and protons around each atom to assign the oxidation states.
The oxidation states are also maintained in articles of the elements (of course), and systematically in the table {{Infobox element/symbol-to-oxidation-state}}
In organic chemistry, the Swern oxidation, named after Daniel Swern, is a chemical reaction whereby a primary or secondary alcohol (−OH) is oxidized to an aldehyde (−CH=O) or ketone (>C=O) using oxalyl chloride, dimethyl sulfoxide (DMSO) and an organic base, such as triethylamine.
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