Halide derivatives

Halide derivatives may be fluorides, chlorides, or bromides. Fluorides are best prepared by the reaction of hydroxy groups with (diethylamino)sulfur trilluoride ( DAST M. Sharma, 1977) or of glycosyl thioethers with DAST/NBS (K.C. Nicolaou, 1990 B). The other halides are usually only introduced at the glycosidic position, where treatment with hydrogen chloride... 

Diene carboxylates can be prepared by the reaction of alkenyl halides with acrylates[34]. For example, pellitorine (30) is prepared by the reaction of I-heptenyl iodide (29) with an acrylate[35]. Enol triflates are reactive pseudo-halides derived from carbonyl compounds, and are utilized extensively for novel transformations. The 3,5-dien-3-ol triflate 31 derived from a 4,5-unsaturated 3-keto steroid is converted into the triene 32 by the reaction of methyl acrylate[36]. 

Halides derived from certain heterocyclic aromatic compounds are often quite reac tive toward nucleophiles 2 Chloropyridme for example reacts with sodium methoxide some 230 million times faster than chlorobenzene at 50°C... 

Perfluoroalkylacecylenic tin compounds have been synthesized via the reaction of perfluoroalkylacetylenic Grignard reagents with tin halide derivatives [21] (equation 14) The stability of several of these perfluoroalkylacetylenic tin derivatives has been studied [22],... 

Enamines in which the vinyl nitrogen system is in conjugation with another functional group can be obtained from reactions of secondary amines with /8-ketoaldehydes and -diketones or their monoenol ether or vinyl halide derivatives (41-46). 

Oxidation of 2-mercapto-l,2,4-triazolo[l,5-c]pyrimidines (174) with chlorine or bromine in water (64BRP951652 65JCS3369), with hydrogen peroxide and chlorine (95MIP1), as well as with sodium chlorate in hydrochloric acid (94JMC2371) gave the corresponding 2-sulfonyl halide derivatives 175. Oxidation of the 2-alkylmercapto compounds 176 to the 2-alkylsufonyl derivatives 177 was made with ammonium peroxodisulfate and sulfuric acid... 

Yamase and Goto406 determined first- and second-order rate coefficients for the aluminium chloride-catalysed reaction of halide derivatives of benzoic acid (lO5 = F, 1.73 Cl, 4.49 Br, 4.35 I, 0.81) and phenylacetic acid (105fc2 = F, 12 Cl, 21 Br, 9 I, 6) with benzene. The maxima in the rates for the acid chloride are best accommodated by the assumption that a highly (but not completely) polarised complex takes part in the transition state. Polarisation of such a complex would be aided by electron supply, and consistently, the acetyl halides are about a hundred times as reactive as the benzoyl compounds (see p. 180, also Tables 105 and 108). 

Reaction of [Cp IrCl2]2 with lithium amidinates provided an entry into a series of Cp Ir[MeC(NR)2]X (X = Cl, Br R = Bu, Cy) complexes as depicted in Scheme 151. The bromide derivative is formed when lithium amidinates containing LiBr are used as starting materials. All halide derivatives are bright orange, crystalline solids that may be stored in air for several weeks without noticeable decomposition. ... 

This fluorescent acid chloride can be used to form derivatives of alcohols, amines, and phenols. Using these fluorescent derivatives, an analysis of a series of n-alcohols from Ci to C4 was developed. A chromatogram produced by this technique is shown in Figure 3. Derivatives were also formed from ammonia, dimethylamine, and phenol. A derivative was formed from pentachlorophenol but was not fully characterized. The quantum yields of fluorescence of the alcohol derivatives of V were lower than those of the alkyl halide derivatives of III. 

Fig. 5.4 View of the structure and intercluster connectivity of the [(ZreBjClia] structure, and mixed halide derivative, respectively. Edge-bridging chlorines are...

The structure of the metal particles dispersed on a silica powder support ( Aerosil 380, 70 A average silica particle diameter) has been studied by Avery and Sanders (47) using electron microscopy in both bright and dark field, to determine the extent to which the metal particles were multiply twinned or of ideal structure. Platinum, palladium, and gold were examined. These catalysts were prepared by impregnation using an aqueous solution of metal halide derivatives, were dried at 100°-150°C, and were hydrogen... 

The testing of germanium halide derivatives of other bulky substituents such as Bu did not afford (GeBu% species. Instead, a variety of polygermane species with interesting structures were isolated [38]. The use of the more bulky -CMeEt2... 

Several gallium halide derivatives of the -C6H3-2,6-Mes2 ligand have been synthesized. The first of these was the compound ClGa(C6H3-2,6-Mes2)275... 

One-electron reduction at the cathode in the presence of cyanide leads to anion-radical of 4-iodonitrobenzene. Like other halide derivatives, 4-iodonitrobenzene in the anion-radical state easily expels the halide ion and converts into 4-nitrophenyl radical. The latter reacts with cyanide ion and produces anion-radical of 4-cyanonitrobenzene. The same anion-radical can be obtained by reducing the 4-cyanobenzenediazonium salt with dithionite in the presence of nitrite. One-electron oxidation with the initial substrate converts this anion-radical into 4-cyanonitrobenzene. 

In model experiments several detailed studies of the solvolyses of glycosyl halide derivatives have been imdertaken 1.24,25) and have led to the conclusion that reaction usually occurs by way of an Sul mechanism (Walden inversions are frequently observed and Sn2 character is known to intrude imder some conditions, notably in solvents of low polarity and in the presence of strong nucleophiles), but no full understanding of the mechanisms of the reactions of these compounds under glycosylating conditions has been achieved. Instead, a realisation of the complex... 

In Hght of the hahde effects, the role of the copper afkoxide and the lithium halide, derived from the transmetaUation, was probed by preparing the copper afkoxide under salt-free conditions (Tab. 10.10) [24, 51, 52]. Initially, mesityl copper, from which the metal hahde salts are removed during preparation [53], was chosen to provide the copper(I) afkoxide. Interestingly, only a trace of product was observed in the absence of hthium... 

Chiral allenylmetal compounds provide convenient access to enantioenriched homopropargylic alcohols through Se2 additions to aldehydes. The syn adducts can be obtained through addition of allenyl tributylstannanes in the presence of stoichiometric boron trifluoride etherate (BF3-OEt2). The use of allenylmetal halides derivatives of Sn, Zn, and In lead to the anti diastereomers. The former additions proceed through an acyclic transition slate whereas the latter are thought to involve a cyclic transition state, thus accounting for the difference in diastereoselectivity. 

Diazomethane is known to react with a large variety of metal halide derivatives, to produce halomethylmetal compounds (107). These reactions may well be... 

The Ammines of Corps , Silver, and Gold—Ammino-derivatives of Cupric Sulphate—Hydroxylamine-derivatives of Cupric Sulphate—Cupro-ammino-sulphates—Ammino-salts of Cuprio Halides—Ammino-ouprous Halides— Ammino-derivatives of Silver Halides—Ammino-derivatives of Silver Nitrate —Ammino-derivatives of Gold Salts—Aurous Halides—Auric Halides— Derivatives of Auric Oxide, Auric Nitrate, Anrie Phosphate, Perohlorate— Derivatives of Mixed Salts. 

Ammino-derivatives of Beryllium and Magnesium Salts—Derivatives of Beryllium Halides—Derivatives of Magnesium Halides. 

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