Sodium periodate, white crystalline powder, soluble in water, acetic acid, hydrochloric acid, sulfuric acid, nitric acid, insoluble in ethanol. Sodium periodate is a white quadrangular crystal that can be dissolved in water and acid. It contains trace impurities such as free acid, chloride, bromide, sulfate and heavy metal. It can be refined by recrystallization from aqueous solution. This kind of material has strong oxidation performance. Although it does not burn itself, under certain conditions, substances that are subject to friction, vibration and impact, high heat or acid and alkali can decompose, burn and explode when they are exposed to moisture, organic substances, reducing agents and substances that are incompatible with nature. Sodium periodate has two main uses in organic synthesis: as oxidant and catalyst. Due to the solubility, the oxidation reaction of sodium periodate is generally carried out in water. Because many organic chemicalbooks are insoluble in water, it is necessary to use cosolvent. When there is a phase transfer catalyst or sodium periodate is loaded on an inert carrier, the oxidation reaction can also be carried out in a two-phase system.
Sodium periodate has two main uses in organic synthesis: on the one hand, it is used as an oxidant; On the other hand, it is used as a catalyst. The oxidation reaction of sodium periodate takes place in water, but for organic matter, it is insoluble in water, so the cosolvent should be used. When there is a phase transfer catalyst composed of quaternary ammonium salt in the two-phase solution, or there is an inert carrier on the surface of the oxidant, the oxidation reaction can also occur.
As a general oxidant, sodium periodate can oxidize alcohols to carbonyl compounds (Formula 1, Formula 2)
Sodium periodate can also be used to break glycol compounds and oxidize them to dicarbonyl compounds (Formula 3, Formula 4)
Sodium periodate even breaks the C=C double bond and oxidizes it to carbonyl compounds. It is called the famous Lemieux-Johnson reagent (formula 6) when combined with OsO4 to oxidize alkenes. In addition, its reduction products can be reused through periodate oxidation.
(Formula 5)
Selective oxidation of sulfide to sulfoxide is a very important reaction, because sulfoxide is a very important intermediate in organic synthesis. It can react with sodium periodate in methanol solution at 0 oC. Sulfide will be oxidized to sulfone at high temperature or by adding excessive sodium periodate. When there is acidic alumina or silica gel, sodium periodate can selectively oxidize sulfide to sulfoxide (high yield can be obtained at room temperature) (Formula 7, Formula 8). The participation of phase transfer catalyst also makes sulfide selectively oxidized to sulfoxide (Formula 9)
In addition, sodium periodate can be used as a cheap catalyst for the sulfonation synthesis of aryl groups (Formula 10).
The reaction conditions are very mild, the yield is high, the reaction time is short, and the selectivity is good.