Additions manganese acetate

O. (R,R)-N,N -Bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamino manga-nese(lll) chloride. A 2-L, three-necked, round-bottomed flask equipped with a mechanical overhead stirrer, reflux condenser, and a 500-mL addition funnel is charged with 67.2 g (0.27 mol 3 eq) of manganese acetate tetrahydrate (Mn(0Ac)2-4H20) and 500 mL of ethanol. Stirring is begun and the solution is heated... 

Manganese acetate-promoted oxidative addition of 1,3-dicarbonyl compounds (351) to endo-cyclic enol ethers (352) and enol lactones (353) gives 2,3,3a,6a-tetrahydrofuro[2,3-6]furan derivatives (354) and (355) <87CL223, 91TL711, 91TL7107). 

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. 

Of striking brevity is the direct addition of acetic acid to 1,1 -dichloro-4-methyl-penta-1,3-diene by means of one-electron oxidising agents like manganese (111) acetate [98], cerium(IV) [99] or vanadium(V) salts. [100,101] The further... 

A multi-method approach was taken by Copeland et al. (2002) for the synthesis of zinc silicate Mn " " phosphors. Prehydrolyzed TEOS, zinc acetate and manganese acetate (2 mol%) were dissolved in ethanol and water. Ammonia solution was added to adjust the pH to greater than 10. In addition, a surfactant (Tween 80) was added to the solution and this was added dropwise to ammonium polyacrylate for obtaining a gel. Purified gels were calcined at 800-1100°C for 2 h. The highest temperature yielded a phase-pure product. 

In our case, Lao,66Sro,33Mn03 was prepared with lanthanum nitrate, lanthanum acetate and lanthanum chloride. After dissolution in water, they were mixed with manganese acetate and strontium nitrate, and then stirred for half an hour. A gel formed after addition of citric acid which protonates the ligands. Ethylene glycol was used for esterification and to improve solubility. Finally ammonium hydroxide was added for peptization, followed by stirring for 1 h. 

SCHEME 4.75 Manganese acetate-promoted addition of phosphites to alkenes [129]. 

Addition of manganese acetate to the electrolyte can also assist in the formation of a good SEI film, which can improve the electrochemical properties of carbon nanotubes. Lil or LiBr can also inhibit the fading of the electrochemical properties of graphite. 

The Perkin reaction is of importance for the iadustrial production of coumarin and a number of modifications have been studied to improve it, such as addition of a trace of iodine (46) addition of oxides or salts of metals such as iron, nickel, manganese, or cobalt (47) addition of catalytic amounts of pyridine (48) or piperidine (49) replacement of sodium acetate by potassium carbonate (50,51) or by cesium acetate (52) and use of alkaU metal biacetate... 

Powdered potassium permanganate (94 mg) is added to an ice-cold, stirred solution of 0.1 g of the unsaturated nitrile in 3.5 ml of acetone containing 0.11 ml of piperidine. The reaction mixture is stirred at 0° for 1.5 hr, allowed to warm to room temperature (30 min) and then treated with 0.02 ml of acetic acid in 0.2 ml of acetone. After stirring at room temperature for an additional 1.5 hr the mixture is treated with chloroform, aqueous sodium bisulfite and sufficient 1 N sulfuric acid to reduce all of the manganese dioxide. 

Medium acid baths, pH 4-5 At this acidity a dichromate solution plus sulphate ion as activator is sufficient to deposit chromate films in 30 min or so at room temperature or in a few minutes at boiling point. Unfortunately, a solution of alkali dichromate and alkali sulphate is quite unbuffered, and other substances must be added to give the bath a useful life over the working pH range. Acetates have been used successfully, but salts of aluminium, chromium, manganese and zinc have been more commonly employed. The pH of the solution rises slowly during use until basic chromates or sulphates begin to precipitate. The solution can then be rejuvenated by the addition of chromic or sulphuric acid or acid salts. 

H. 8-Hydroxyquinaldine (XI). The reactions of 8-hydroxyquinaldine are, in general, similar to 8-hydroxyquinoline described under (C) above, but unlike the latter it does not produce an insoluble complex with aluminium. In acetic acid-acetate solution precipitates are formed with bismuth, cadmium, copper, iron(II) and iron(III), chromium, manganese, nickel, silver, zinc, titanium (Ti02 + ), molybdate, tungstate, and vanadate. The same ions are precipitated in ammoniacal solution with the exception of molybdate, tungstate, and vanadate, but with the addition of lead, calcium, strontium, and magnesium aluminium is not precipitated, but tartrate must be added to prevent the separation of aluminium hydroxide. 

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