Alkenes manganese salts

Addition of phosphonyl radicals onto alkenes or alkynes has been known since the sixties [14]. Nevertheless, because of the interest in organic synthesis and in the initiation of free radical polymerizations [15], the modes of generation of phosphonyl radicals [16] and their addition rate constants onto alkenes [9,12,17] has continued to be intensively studied over the last decade. Narasaka et al. [18] and Romakhin et al. [19] showed that phosphonyl radicals, generated either in the presence of manganese salts or anodically, add to alkenes with good yields. 

The epoxidation of alkenes using iodosylbenzene, with tetra-n-butylammonium bromide and a manganese or cobalt polytungstate as co-catalysts [24], appears to have little advantage as a synthetic procedure over other methods. n-Hexene produces the oxirane (58%), when catalysed by the manganese salt, whereas norbornene is more readily converted (96%) into the oxirane with the cobalt salt. 

The aziridination of alkenes, catalytic in porphyrinatoiron and -manganese salts, has been developed where the nitrene moiety is supplied by A -(4-methylphenylsulfonyl)iminophenyl-iodinane (C6H5I = NTs) and the reaction intermediate is a high-valent tosylimidometal species (Table 9)98-10°. This intermediate may undergo addition to an alkene double bond by a free radical mechanism or via a four-membered metallocycle. 

Sodium hexakis(formato)molybdate, 3, 1235 Sodium hypochlorite alkene epoxidation manganese catalysts, 6,378 Sodium ions biology, 6, 559 selective binding biology, 6, 551 Sodium molybdate, 3, 1230 Sodium peroxoborate, 3,101 Sodium/potassium ATPase, 6, 555 vanadate inhibition, 3, 567 Sodium pump, 6, 555 mechanism, 6, 556 Sodium pyroantimonate, 3, 265 Sodium salts... 

Many transition-metal complexes have been widely studied in their application as catalysts in alkene epoxidation. Nickel is unique in the respect that its simple soluble salts such as Ni(N03)2 6H20 are completely ineffective in the catalytic epoxidation of alkenes, whereas soluble manganese, iron, cobalt, or copper salts in acetonitrile catalyze the epoxidation of stilbene or substituted alkenes with iodosylbenzene as oxidant. However, the Ni(II) complexes of tetraaza macrocycles as well as other chelating ligands dramatically enhance the reactivity of epoxidation of olefins (90, 91). 

Recently it has been shown that simple manganese sulfate in the presence of sodium bicarbonate is reasonably effective in promoting the epoxidation of alkenes with aqueous H202 using DMF or t-BuOH as solvents [69]. In this system peroxo-carbonate is formed in situ, thus minimizing the catalase activity of the Mn salt. Following this discovery, Chan and coworkers introduced an imidazole-based ionic... 

Ethylene oxide is manufactured by oxidizing ethylene with air or oxygen in the presence of a silver catalyst Alkenes furnish hydroperoxides when oxidized by oxygen in the presence of catalysts like salts of cobalt and manganese the hydroperoxides are transformed to a number of products, including epoxides. Only in a few cases, such as oxidation of 1-phenylcyclooctene, have moderate yields of epoxides been obtained during autoxidation. ... 

Manganese(III) acetate or chloride salts [Mn30(0Ac)7H0Ac, MnCh] can react with alkenes to afford... 

Manganese (III) acetate or chloride salts [Mn30(0Ac) H0Ac, MnCb] can react with alkenes to afford 1,2-dichlorides and chlorohydrin acetates (equation 16). i The manganese(III) reagent promotes the chlorination of 1,6-heptadiene (42) to afford almost equal amount of open chain and cycliz dichlorides... 

Allylic acetoxylation with palladium(II) salts is well known however, no selective and catalytic conditions have been described for the transformation of an unsubstituted olefin. In the present system use 1s made of the ability of palladium acetate to give allylic functionalization (most probably via a palladium-ir-allyl complex) and to be easily regenerated by a co-oxidant (the combination of benzoquinone-manganese dioxide). In contrast to copper(II) chloride (CuClj) as a reoxidant,8 our catalyst combination is completely regioselective for allcyclic alkenes with aliphatic substrates, evidently, both allylic positions become substituted. As yet, no allylic oxidation reagent is able to distinguish between the two allylic positions in linear olefins this disadvantage is overcome when the allylic acetates are to... 

As previously noted, optically active trans-epoxides are not easily available through the (salen)Mn-catalyzed epoxidation of rrans-olefins. However, a modification in the conditions for cis-alkene epoxidation can provide access to trans-epoxides [94JA6937]. Addition of an cinchona alkaloid derivative such as 18 promotes a remarkable crossover in diastereoselectivity, such that the trans-epoxide 17 can be prepared in 90% de from cis-B-methylstyrene (16). It is not yet clear whether these chiral quaternary ammonium salts fundamentally change the nature of the manganese-based oxidant, or rather somehow prolong the lifetime of the radical intermediate, allowing rotation before collapse. 

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