Tetraethylammonium halide

Trans-esterification of ethylene carbonates (3.3.1.F) produces (i-hydroxyethyl esters in good yield (>70%), when the reaction is catalysed by tetraethylammonium halides [36]. 

The monocyclic dithiolato halo plumbates, 86a-c, were synthesized by the condensation of diphenyllead dichloride with toluene-3,4-dithiol in the presence of Et3N, followed by the addition of tetraethylammonium halide as shown in equation 15327. 

Another example for mono-chelate complexes investigated for their antitumour activity857 consists of tetraethylammonium halide adducts 485 (X = Hal, R = Aik, Ar) containing 0,N,0-tridentate dianionic ligand. 

From relative solubilities (eqn. 20) of silver halides in DMSO and in water (Lnehrs e< ol., 1966) (cf. Table 5). From partial molar heats of solution of tetraethylammonium halides in DMSO and in water. (Arnett and McKelvey, 1966). 

Another very valuable principle for glycosidation reactions, introduced by Lemieux,8 is the so-called halide ion-catalyzed glycosidation reaction. In an equilibrium reaction with tetraethylammonium halide, an a-D-glycosyl halide that is more stable can be converted into the thermodynamically less stable /3-D anomer, which may be present in much lower concentrations. The latter, however, reacts... 

Methyl, ethyl, and benzyl ethers have been prepared in the presence of tetraethylammonium fluoride as a Lewis base (alkyl halide, DME, 20°, 3 h, 60-85% yields). ... 

The application of phase-transfer catalysis to the Williamson synthesis of ethers has been exploited widely and is far superior to any classical method for the synthesis of aliphatic ethers. Probably the first example of the use of a quaternary ammonium salt to promote a nucleophilic substitution reaction is the formation of a benzyl ether using a stoichiometric amount of tetraethylammonium hydroxide [1]. Starks mentions the potential value of the quaternary ammonium catalyst for Williamson synthesis of ethers [2] and its versatility in the synthesis of methyl ethers and other alkyl ethers was soon established [3-5]. The procedure has considerable advantages over the classical Williamson synthesis both in reaction time and yields and is certainly more convenient than the use of diazomethane for the preparation of methyl ethers. Under liquidrliquid two-phase conditions, tertiary and secondary alcohols react less readily than do primary alcohols, and secondary alkyl halides tend to be ineffective. However, reactions which one might expect to be sterically inhibited are successful under phase-transfer catalytic conditions [e.g. 6]. Microwave irradiation and solidrliquid phase-transfer catalytic conditions reduce reaction times considerably [7]. 

The complexes undergo weak antiferromagnetic interactions with exchange proceeding via the halide bridges. The counterion may have a marked effect on the structure for [Cr2Cl9]3-, change of the counterion from potassium to tetraethylammonium is accompanied by a decrease... 

Triphenylphosphine-Diethyl azodi-carboxylate-Lithium halides, 332 by bromide Sodium bromide, 46 Tetraethylammonium bromide, 46 Triphenylphosphine-Diethyl azodi-carboxylate-Lithium halides, 332 by iodide Sodium iodide, 46 Sodium iodide-Boron trifluoride etherate, 282... 

Iron halides react with halide salts to afford anionic halide complexes. Because iron(III) is a hard acid, the complexes that it forms are most stable with F and decrease in both coordination number and stability with heavier halides. No stable I complexes are known. [FeF5(H20)]2 is the predominant iron fluoride species in aqueous solution. The [FeF6]3 ion can be prepared in fused salts. Whereas six-coordinate [FeClJ3 is known, four-coordinate complexes are favored for chloride. Salts of tetrahedral [FeClJ can be isolated if large cations such as tetraphenylarsonium or tetraalkylammonium are used. [FeBrJ is known but is thermally unstable and disproportionates to iron(II) and bromine. Complex anions of iron(II) halides are less common. [FeClJ2 has been obtained from FeCl2 by reaction with alkali metal chlorides in the melt or with tetraethylammonium chloride in deoxygenated ethanol. 

Other base systems have been also studied, including tetraethylammonium superoxide [53], basic resins [54], Triton-B (benzyltrimethylammonium hydroxide) [55], and K2C03 in the presence of catalytic amounts of (Bu4N)I [56]. In a few cases, the use of alkyltosylates, as alkylating agents in place of alkyl halides, has been also investigated [54b, 55b, 56]. 

For this reason, electrophilic additions such as addition of hydrogen halides are very difficult, as can be seen in Explanations 13, 14, and 15. But because of the low overall electron density, the double bonds in perfluoroalkenes are easily attacked by nucleophiles such as fluoride ion. If perfluoropropene is treated with dry potassium fluoride in a proton-donor solvent such as formamide, the fluoride anion joins the less negative carbon of the double bond and forms a negatively charged intermediate that readily reacts with the proton of formamide to give 2 H-perfluo-ropropane [5/]. Such a nucleophilic addition takes place with other fluorides such as cesium fluoride, tetraethylammonium fluoride, and sil-... 

The most commonly used quaternary ammonium salts are tetrabutylammonium perchlorate (TBAP), tetrafluoroborate (TBAT), the halides (TBACl, TBAB, and TBAI), and the corresponding tetraethylammonium salts, such as the perchlorate (TEAP), but also the tetramethyl- or tetrapropylammonium salts have been employed the former cannot undergo a base-promoted Hofmann elimination. However, evidence has been found for the formation of trimethylammonium methylide [460]. In nonpolar solvents it may be necessary to employ tetrahexyl- or tetraoctylammonium salts. The tetraalkylammonium ions are soluble in many nonaqueous media, and they may be extracted from an aqueous solution by means of chloroform or methylene chloride [461,462], and tetraalkylammonium salts may thus be prepared by ion extraction [462]. Tetrakis(decyl)ammonium tetra-phenylborate is soluble even in hexane [442,443]. 

Thallium(I) cyanide was introduced by Taylor and McKillop as a reagent. Aromatic and heteroaromatic acyl cyanides are produced in go yield, whereas aliphatic acid halides lead under these conditions mainly to dimerization products. 18-Crown-6 is a good catalyst for the preparation of cyanoformate in methylene chloride with potassium cyanide and chloroformates. Similarly, tetraethylammonium cyanide gives cyanoformates in high yield under very mild conditions. Aroyl cyanides are generated easily by phase transfer catalysis with tetra-n-butylammonium bromide. Tri- -butyltin cyanide proved successful only with aromatic acid halides, leading to dimerization products with aliphatic compounds. ... 

Tetraethylammonium borohydride reduces diphenyl diselenide to phenylselenolate anion. When an acyl halide is added to the toluene solution of phenylselenolate anion, the corresponding acylation product is isolated in good yield (equation 4). Resin-supported phenyl selenide anion underwent acylation with acetyl chloride under mild reaction conditions. ... 

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