Magnesium chloride promoters

Magnesium chloride promoted Michael additions of these compounds to unsaturated carbonyl compounds were achieved with moderate to good asymmetric induction. Chiral organotin enamines were prepared from... 

The effect of other electrolytes is also of interest. Addition of divalent cations, e.g., in the form of calcium and magnesium chloride salts, results in precipitation of the anionic vesicles, which is also observed for micelles in water. There is, however, a significant trend within the alkali metal cations, e.g., from Na+ to Rb+. The larger rubidium ion has a promotional effect on the formation of vesicles, and indeed with Cs+, vesicles are already formed on the addition of trace amounts of salt. The relevant data are shown in Fig. 19.8. 

These aminohydroxy compounds in the form of their salts are extremely useful as catalysts for permanent press resins. The utilization of these compounds alone or in combination with metal salts such as magnesium chloride or zinc nitrate promotes balanced curing action with a wide range of textile resins. These catalysts provide ... 

In terms of catalyst development, the next sequence of reactions shows the evolution of one series of Ziegler-Natta materials. The initial reaction exhibits the simple characteristics of a chlorination reaction. The addition of the ethylorthosilicate reactant increases the rate of reaction and yields a purer solid phase. By optimizing the reactivity of the chlorination promoter, the conversion of the Grignard reagent to magnesium chloride can be forced to occur even faster. The magnesium chloride product from this reaction is composed of fine particles that lack appreciable crystallinity and exhibit high BET surface... 

Filtered sodium is reabsorbed at the proximal tubules, the Loop of Henle, distal tubules, or in the collecting tubules. Diuretics influence tubules closest to the glomeruli, causing natriuresis (sodium loss in the urine). Diuretics cause loss of other electrolytes (potassium, magnesium, chloride, bicarbonate). Diuretics that promote potassium excretion are called potassium-wasting diuretics or potassium-sparing diuretics. 

Bicyclo[4.1.0]heptan-2-ol 8 was also cleaved by magnesium halides, or a mixture of zinc and magnesium halides. Magnesium chloride afforded a good yield of 4-chlorocycloheptene (9), but the magnesium bromide or iodide promoted rearrangements, with or without zinc halide, gave mainly 3-(halomethyl)cyclohexenes. ... 

Many diuretics cause loss of other electrolytes, including potassium, magnesium, chloride, and bicarbonate. The diuretics that promote potassium excretion are classified as potassium-wasting diuretics. Potassium-sparing diuretics promote the reabsorption of potassium. Combination diuretics have been marketed that have both actions. 

The magnesium supports used for polyethylene catalysts could be modified for use in polypropylene production, and magnesium chloride proved to be the most suitable when used with a Lewis base election donor. Milled magnesium chloride was known to have the same layer stracmre as a- and y-titanium trichloride with the quadrivalent titanium ion (0.068 nm diameter), being about the same size as the divalent magnesium ion (0.066 nm diameter). In 1968, Montedison and Mitsui Petrochemical Industries both disclosed the production of a highly active, very steieospecific catalyst that contained about 3% titanium on a magnesium chloride support, promoted with a Lewis base, such as ethyl benzoate. The polymer produced contained less than 1 ppm titanium with an isotactic index of more than 90%, which was improvement on the product made with previous catalysts. 

The majority of catalytic enantioselective allylation reactions involve the chiral Lewis-acid-catalysed additions of allylsilanes or allylstannanes to carbonyl compounds. Monothiobinaphthol has been used by Woodward et al. as a chiral promoter in the enantioselective catalytic allylation of aryl ketones with impure Sn(allyl)4, prepared from allyl chloride, air-oxidised magnesium and SnCl4. Therefore, the allylation of arylketones in these conditions was achieved very efficiently, since the corresponding allylic alcohols were formed in... 

This must reflect activation of the carbonyl group by magnesium ion, since ketones are less reactive to pure dialkylzinc reagents and tend to react by reduction rather than addition.141 The addition of alkylzinc reagents is also promoted by trimethylsilyl chloride, which leads to isolation of silyl ethers of the alcohol products.142... 

Coupling of acetylenes and halides, copper-promoted, 50,100 Cuprous chloride, reaction with an organo-magnesium compound, 50,98... 

N-Alkylation is favored by sodium and potassium cations, whereas C-alkylation is promoted by the more strongly coordinating lithium and magnesium cations (90JCS(P1)111). N-Alkylation is also favored by polar solvents and the use of tosylates rather than iodides. Under phase transfer conditions, the preference for A-alkylation in indoles ranges from 1.5 1 for benzyl bromide to 10 1 for benzyl chloride and -alkyl bromides, over 3-alkylation (90H(31)447). 

Magnesium bromide, zinc chloride, and other Lewie adds aie capable of cleaving epoxy ethers with great facility, 708 1708 the presence of a polar substituent on the epoxide ring promoting rupture... 

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