Phosphonium permanganates, reactions

Transition metal oxidants such as permanganate, ruthenium tetroxide and diromium(VI) oxide are convenient and efficient reagents for routine cleavage reactions. The use of phase transfer catalysts (quaternary ammonium and phosphonium ions, primarily) has made it possible to solubilize transition metal oxides such as permanganate and chromatt in nonaqueous solvents, and to therdry increase the scope of these reactions substantially. ... 

SoHd-liguid phase-transfer catalysis. Crown ethers have commonly been used as catalysts for reactions between a solid-liquid interface, and quaternary ammonium and phosphonium salts have been used only as catalysts for reactions in two-phase liquid liquid reactions. However, several laboratories have reported that the latter catalysts are also satisfactory for two-phase solid liquid reactions. Thus dichlorocarbene can be generated from chloroform and solid sodium hydroxide under catalysis from benzyltriethylammonium chloride in yields comparable to those of the classical Makosza method. Another example of this type of catalysis is the oxidation of terminal and internal alkynes by solid potassium permanganate in CH2CI2 with Adogen 464 as catalyst. Aliquat 336 has been found to be as satisfactory as a crown ether for certain displacement reactions with NaOAc, KSCN, KNOa, and KF in CH3CN or CHaCla. ... 

Introduction. Sodium periodate is widely used for the oxidation of a variety of organic substrates and as a cooxidant in other oxidation reactions (see Sodium Periodate-Osmium Tetroxide and Sodium Periodate-Potassium Permanganate) f The Nal04 oxidation is usually conducted in water however, for organic substrates that are insoluble in water, an organic cosolvent (e.g. MeOH, 95% EtOH, 1,4-dioxane, acetone, MeCN) is used. Alternatively, the oxidation can be conducted either with phase-transfer catalysis (PTC) using quaternary ammonium or phosphonium salts in a two-phase system, or in an organic solvent if the oxidant is first coated on an inert support. ... 

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