Reduction reaction ether solutions

Arsine, AsHs, is formed when many As-containing compounds are reduced with nascent hydrogen and its decomposition on a heated glass surface to form a metallic mirror formed the basis of Marsh s test for the element. The low-temperature reduction of AsCls with LiAlH4 in diethyl ether solution gives good yields of the gas as does the dilute acid hydrolysis of many arsenides of electropositive elements (Na, Mg, Zn, etc.). Similar reactions yield stibine, e.g. ... 

In the reduction of acids there is a tendency for the lithium salt, RCO20Li to separate from the ethereal solution, and thus bring reduction to a halt this can be avoided by first converting the acid to a simple, e.g. Me or Et, ester. In the reduction of the latter, the initial nucleophilic attack by AIH4 results in an addition/elimination reaction—OR is a good leaving group in (40)—followed by normal attack, as above, on the resultant carbonyl compound (41) to yield the primary alcohol (42) ... 

The reduction of free acids to alcohols became practical only after the advent of complex hydrides. Lithium aluminum hydride reduces carboxylic acids to alcohols in ether solution very rapidly in an exothermic reaction. Because of the presence of acidic hydrogen in the carboxylic acid an additional equivalent of lithium aluminum hydride is needed beyond the amount required for the reduction. The stoichiometric ratio is 4 mol of the acid to 3 mol of lithium aluminum hydride (Equation 12, p. 18). Trimethylacetic add was reduced to neopentyl alcohol in 92% yield, and stearic acid to 1-octadecanol in 91% yield. Dicarboxylic sebacic acid was reduced to 1,10-decanedioI even if less than the needed amount of lithiiun aluminum hydride was used [968]. 

When lithium aluminium hydride, Li(AlH4), in ether solution is used instead of lithium hydride for the reduction of OPCI3, the OPH3 also formed is mostly further reduced to phosphine at temperatures of about -115 °C. Altogether, the reaction can be described by the following equations ... 

The reduction of phenanthridine to 5,6-dihydrophenanthridine (90, R = H) was readily accomplished by reaction with lithium aluminum hydride in ethereal solution.118 The same dihydrophenanthridine resulted from the lithium aluminum hydride reduction of 6-chloro-phenanthridine or phenanthridone,1180 thus confirming the position of saturation of the product.119 It is of interest to note that molecular complexes of phenanthridine and dihydrophenanthridine were not observed as products in this reduction as was the case in the metal hydride reduction of phenazine.119... 

Bohlmann97 reported that an ethereal solution of quinoxaline (99) on treatment with lithium aluminum hydride resulted in partial reduction of the nitrogenous heterocyclic ring, 1,2,3,4-tetrahydro-quinoxaline (100) being the sole product of the reaction. Similar... 

It should be noted that if the ethereal solution is contaminated with protic substances at too high a level, the alkali metal might be passivated with the reduction products of the contaminants. Consequently, the reaction between the active metal and the benzophenone does not take place, and no absorption of contaminants occurs. When the benzophenone does react with the alkali metal and the... 

Ether solutions based on TAA salts are not reduced on noble metal electrodes. The major cathodic reaction of these solutions involves the cation reduction to trialkyl amine, alkane, and alkene (which are the stable disproportion products of the alkyl radical formed by the electron transfer to the cation) [3], Electrolysis of ethers such as THF or DME containing TBAP, formed in the catholyte tributyl amine, butane and butene, were unambiguously identified by NMR and GCMS analysis [3], In the presence of water (several hundred ppm and more), the electrolysis products were found to be tributyl amine and butene (butane was not detected) [3], The potential of this reduction reaction is higher than that of the dry solution, and it is clear that the initial electroactive species in this case is the... 

In reviewing the intrinsic electrochemical behavior of nonaqueous systems, it is important to describe reactions of the most common and unavoidable contaminants. Some contaminants may be introduced by the salts (e.g., HF in solutions of the MFX salts M = P, B, As, etc.). Other possible examples are alcohols, which can contaminate esters, ethers, or alkyl carbonates. We examined the possible effect of alcoholic contaminants such as CH3OH in MF and 1,2-propylenegly-col at concentrations of hundreds of ppm in PC solutions. It appears that the commonly used ester or alkyl carbonate solvents are sufficiently reactive (as described above), and so their intrinsic reactivity dominates the surface chemistry if the concentration of the alcoholic contaminant is at the ppm level. We have no similar comprehensive data for ethereal solutions. However, the most important contaminants that should be dealt with in this section, and which are common to all of these solutions, are the atmospheric ones that include 02, H20, and C02. The reduction of these species depends on the electrode material, the solvent used, and their concentration, although the cation plays the most important role. When the electrolyte is a tetraalkyl ammonium salt, the reduction products of H20, 02 or C02 are soluble. As expected, reduction of water produces OH and... 

Benzidine.—That nitrobenzene, by electrolytical reduction in acid solution, can directly yield benzidine, was first proved by Hiiussermann,1 who used sulphuric acid. Lob 2 later proved the same to be true for hydrochloric-, acetic- and formic-acid electrolytes. However, several reactions predominate in this direct acid reduction, which prevent the carrying out of the reaction up to hydrazobenzene, or the formation of benzidine. Phenylhydroxylamine may particularly be mentioned in this connection. In alcoholic-acid solution it is partly rearranged to amidophenol or its ethers, and partly reduced to aniline. Azoxybenzene, in acid solution, is the starting-point in the benzidine formation however, in this case, the combining velocity of nitrosobenzene and phenylhydroxylamine is not very great, so that the latter is to a very considerable extent subject to the more rapidly acting influence of the acid. 

Diethyl (trimethylsilyl) phosphine has been prepared by the reaction of lithium diethylphosphide with chlorotrimethyl-silane in ether solution.4 The lithium diethylphosphide may be prepared by the reaction of an ether solution of phenyllithium with diethylphosphine.6 However, the dialkylphosphines are most conveniently prepared by the reduction of the corresponding tetraalkyldiphosphine disulfides with lithium tetrahydro-aluminate in ether.6 7 An alternative method for the preparation of dimethyl(trimethylsilyl)phosphine which eliminates the handling of the volatile dimethylphosphine involves the preparation of lithium dimethylphosphide from tetramethyldiphosphine. The latter is prepared by the reduction of tetramethyldiphosphine disulfide8 with tributylphosphine.9 The reaction of chlorotrimethylsilane with lithium dimethylphosphide is most conveniently carried out in a vacuum system without solvent at -78°. 

Based on the benzyl derivative (26), the first stable carborane-containing simple enol (27) was synthesized2 (Scheme 8). The acid chloride (28) readily enters into a Friedel-Crafts reaction with mesitylene to give ketone (29). Under the action of BuLi on a benzene-ether solution of ketone (29) enolate (30) is formed. Treatment of the latter with diluted HC1 solution results in enol (27). Starting from the benzyl derivative (31), carboranyl-substituted indene (32) was synthesized by intramolecular cyclization with a formation of ketone (33), whose reduction (34) followed by dehydration results in (32) (Scheme 9). 

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