Methanesulfonic halides

Typically, the organic substrate in these reactions is a haloalkane. Primary haloalkanes will generally give 100% substitution products, but tertiary and cyclohexyl halides usually undergo 100 % elimination, with secondary haloalkanes producing a mixture of the two. Studies of the chloride and bromide displacements of (R)-2-octyl methanesulfonate have shown that phase transfer displacements proceed with almost complete inversion of stereochemistry at the carbon centre, indicating an Sjv2-like mechanistic pathway [41],... 

Krypton difluoride, 4313 Potassium hexaoxoxenonate-xenon trioxide, 4674 Tetrafluoroammonium hexafluoroxenate, 4386 Xenon difluoride dioxide, 4322 Xenon difluoride oxide, 4319 Xenon difluoride, 4332 Xenon hexafluoride, 4377 Xenon tetrafluoride, 4353 Xenon tetrafluoride oxide, 4346 Xenon tetraoxide, 4863 Xenon trioxide, 4857 Xenon(II) fluoride methanesulfonate, 0443 Xenon(II) fluoride perchlorate, 3977 Xenon(II) fluoride trifluoroacetate, 0634 Xenon(II) fluoride trifluoromethanesulfonate, 0356 Xenon(IV) hydroxide, 4533 Xenon(II) pentafluoroorthoselenate, 4382 Xenon(II) pentafluoroorthotellurate, 4383 Xenon(II) perchlorate, 4110 See Other NON-METAL HALIDES, NON-METAL OXIDES... 

Cleavage of C—O bonds by direct electron transfer from a cathode is usually difficult because of the negative reduction potential of the bond. Therefore, the reduction of aliphatic alcohols (R-OH) to the corresponding hydrocarbons (R-H) is often carried out by the transformation of hydroxyl groups to good leaving groups such as halides (X = Br, I), methanesulfonates (OMs), and... 

Table II. Catalytic Activity of Sandwich Ligands 1 and 2 in Nucleophilic Substitutions on n-Octyl Methanesulfonate with Alkali Halides (MY) under Solid-Liquid Conditions in Toluene at 50°C...

Earle et al reported the first proof of the paradigm that the outcome of a chemical reaction can be radically altered by the choice of the ionic liquid as the solvent for the catalyst. The reactants were toluene and nitric acid in HCl for the following three ILs (1) [bmim][OTf, (2) [bmim][X], and (3) [bmim][OMs] where OTf is the trifluoromethanesulfonate anion, X = halide, and OMs = methanesulfonate salt. The reactions observed are described in Scheme 1. 

In contrast to alkyl halides, methanesulfonates and 4-methylbcnzenesulfonates, alkyl trifluo-romethanesulfonates react with lithiated dialkoxydihydropyrazincs 1, derived from a-methylphenylalanine and glycine, to give predominantly 56% de r/.v-adducts 2, as shown with 2-bromoethyl-/-d, trifluoromethanesulfonatels. 

A better leaving group to exchange with halide anions is a methanesulfonate orp-toluene-sulfonate (tosylate). Thus, potassium salts in aqueous solutions of all the halides react with methyl octanesulfonate under mild conditions in presence of either tributylhexadecylphosphonium bromide200,201 or dicyclohexano-18-crown-6202 catalysts (equation 17) ... 

Indoles can be 3-alkylated by allyl alcohols in the presence of lithium perchlorate and acetic acid 101 is an example (Scheme 42). Pyrrole -alkylation can be achieved with simple alkyl halides [1-bromopentadecane, l-(bromomethyl)-, l-(3-chloropropyl)- and l-(3-iodopropyl)benzenes, 2-(2-bromoethyl)- and 2-(3-bromopropyl)naphthalenes] and mesylates [3-phenylpropyl-, l-methyl-3-phenylpropyl-, 2-(2-naphthyl)ethyl- and 3-(2-naphthyl)propyl methanesulfonates] selectively at C(2) and C(5) positions via reaction in various ionic liquids (e.g., Scheme 43) <20050L1231>. 

The conversion of an alcohol to a methanesulfonate or an alkyl halide followed by nucleophilic displacement with an alkoxide is a milder... 

Amines can displace a halide or a derivative of an alcohol, such as the methanesulfonate or toluene-4-sulfonate, with the eventual formation of a quaternary ammonium salt. Reaction with ammonia may lead to mixtures, since the initial alkylation increases the basicity of the nitrogen, and hence the primary amine reacts more rapidly than ammonia. Further reaction, although enhanced by the increase in basicity, may be impeded by steric hindrance arising from the additional alkyl groups. 

Sulfonates do not necessarily show the same reaction pattern as halides. It has been reported that p-toluenesulfonate (51a) and methanesulfonate (51b) reacted with azide ion and cyanide ion to give (52a) and (52b), while iodide (51c) gave (53a) and (53b) (Scheme 22). ... 

In contrast to the anion of diethyl phosphoramidate or trifluoromethanesulfonamide, which cannot be cleanly monoalkylated, - the anion of trifluoroacetamide (100) was monoalkylated by alkyl halides or alkyl methanesulfonate. The resulting A -alkylamides (101) were converted into primary amines by alkaline hydrolysis or reduction (NuBHa Scheme 42). Various primary amines were prepared from (100) with primary alkyl iodides or methanesulfonate, benzyl and allyl halides, a-bromocarbonyl compounds and 2,4-dinitrochlorobenzene. However, competitive elimination is a serious side reaction for less reactive primary alkyl chlorides and secondary halides or methanesulfonate. The synthesis of secondary amines from (100) has also been reported. ... 

Metaphosphoric acid, 665-666 Methacrolein, 467 Methallyl halide, 915, 1040 Methallyl isocyanate, 1172 Methanq>hosphonyl dichloride, 666 Methanesulfonic acid, 458, 666-667,791 Methanesulfonic anhydride, 667 Methanesulfonyl chloride, see Mesyl chloride... 

In contrast, if halide-based ionic liquids were used under similar conditions, halogenated products were isolated. If hydrochloric acid was used in a nitrate-based ionic liquid, halogenated products also resulted. In methanesulfonate-based ionic liquids, nitric acid acts as an oxidising agent rather than a nitrating agent, which is capable of oxidising toluene to benzoic acid. Likewise it was possible to use a nitrate-based ionic liquid with added methanesulfonic acid [127],... 

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