Manganese acetate reaction with alkenes

Polycyclic y-lactones. An intramolecular version of the formation of y-lactones by reaction of an alkene with acetic acid and manganese(HI) acetate (1) (6, 355-356) provides a general route to polycyclic y-lactones. Thus the unsaturated p-keto acid 2 cyclizes to the ds-bicyclic y-lactone 3 when warmed in acetic acid with 1 (1.3 equiv.)2... 

Other oxidative double bond azidations have been reported. Thus an azidohydrin was formed from pregnenolone acetate and chromyl azide (NaNs, Chromium(VI) Oxide) and steroidal dienones reacted with TMSNs/Leadf/V) Acetate to give diazido compounds. Vicinal diazides also result from alkenes and Fe Manganese(IH) Acetate (eq 9), or lodosylbenzene and NaNs. Anti-Markovnikov selenoazido products were prepared from the reaction of azide ion with alkenes and (Diace-toxyiodo)benzene/Diphenyl Diselenide (eq 10) a-keto azides (with TMSN3) are formed without PhSeSePh. ... 

Scheme 4 Reaction of alkenes with tris(2,4-pentanedionato)manganese(III) in acetic acid at room temperature in air...

A similar reaction of alkenes with 2,4-piperidinediones was carried out using a catalytic amount of manganese(III) acetate until the 2,4-... 

The synthesis of functionalized 1,2-dioxane derivatives was developed using the tris(2,4-pentanedionato)manganese(lll)-alkene system and the man-ganese(III) acetate-1,3-dicarbonyl compoimd-alkene system. The endoper-oxidation catalytically proceeded in air imder very mild reaction conditions and the excellent yield of the endoperoxides was achieved, hi addition, heterocycle-fused or -substituted dioxanes could be synthesized according to the manganese(III)-catalyzed endoperoxidation. The hydroperoxidation also occurred in the reaction of the cyclic 1,3-diamides with alkenes. Furthermore, the direct hydroperoxidation of the cyclic 1,3-diamides was effective in the absence of alkenes. 

The reaction of //-phosphinates (712) with alkenes (713) in the presence of catalytic amounts of manganese(ii) acetate provided a simple and inexpensive way to prepare either symmetrically or differentially disub-stituted phosphinates (714) in moderate to good yields (Scheme 197). On the other hand, a direct heterocyclisation of (715) via intramolecular radical atylation, has been achieved using manganese(ii) acetate and excess of manganese(ii) oxide (Scheme 198). ... 

A hydroxy and an arylthio group can be added to a double bond by treatment with an aryl disulfide and lead tetraacetate in the presence of trifluoroacetic acid." Manganese and copper acetates have been used instead of Pb(OAc)4. ° Addition of the groups OH and RSO has been achieved by treatment of alkenes with O2 and a thiol (RSH)." Two RS groups were added, to give vie- dithiols, by treatment of the alkene with a disulfide RSSR and Bp3-etherate."° This reaction has been carried... 

In the presence of dioxygen, the carbon radical R- produced by reactions (201) and (202) ar transformed into alkylperoxy radicals ROO, reacts with Co or Mn species to regenerate th Co " or Mn " oxidants, and produce primary oxygenated products (alcohol, carbonyl compounds which can be further oxidized to carboxylic acids. This constitutes the basis of several Industrie processes such as the manganese-catalyzed oxidation of n-alkenes to fatty acids, and the cobal catalyzed oxidation of butane (or naphtha) to acetic acid, cyclohexane to cyclohexanol-on mixture, and methyl aromatic compounds (toluene, xylene) to the corresponding aromatic monc or di-carboxylic acids. ... 

Manganese(III)-mediated radical reactions have become a valuable method for the formation of carbon-carbon bonds over the past thirty years since the oxidative addition of acetic acid (1) to alkenes to give y-butyrolactones 6 (Scheme 1) was first reported by Heiba and Dessau [1] and Bush and Finkbeiner [2] in 1968. This method differs from most radical reactions in that it is carried out under oxidative, rather than reductive, conditions leading to more highly functionalized products from simple precursors. Mn(III)-based oxidative free-radical cyclizations have been extensively developed since they were first reported in 1984-1985 [3-5] and extended to tandem, triple and quadruple cyclizations. Since these additions and cyclizations have been exhaustively reviewed recently [6-11], this chapter will present an overview with an emphasis on the recent literature. 

Manganese(III) can oxidize carbonyl compounds and nitroalkanes to carboxy-methyl and nitromethyl radicals [186]. With Mn(III) as mediator, a tandem reaction consisting of an intermolecular radical addition followed by an intramolecular electrophilic aromatic substitution can be accomplished [186, 187). Further Mn(III)-mediated anodic additions of 1,3-dicarbonyl and l-keto-3-nitroalkyl compounds to alkenes and alkynes are reported in [110, 111, 188). Sorbic acid precursors have been obtained in larger scale and high current efficiency by a Mn(III)-mediated oxidation of acetic acid acetic anhydride in the presence of butadiene [189]. Also the nitromethylation of benzene can be performed in 78% yield with Mn(III) as electrocatalyst [190]. A N03 radical, generated by oxidation of a nitrate anion, can induce the 1,4-addition of aldehydes to activated olefins. NOj abstracts a hydrogen from the aldehyde to form an acyl radical, which undergoes addition to the olefin to afford a 1,4-diketone in 34-58% yield [191]. 

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