Sulfonates, secondary alkyl

In the solvolysis of secondary alkyl sulfonates, competition between nucleophilic solvation and electron donation by the substituents results in a significantly solvent-dependent p, which varies from — 9 to — 1 on going from the non-nucleophilic hexafluoro-2-propanol to 80% aqueous ethanol (Bentley et al, 1981). In contrast, the p -invariance for alkene bromination in H20, M70, MeOH and AcOH [equations (22)-(25)] seems to imply a perfect balance between the two types of charge stabilization. However, this conclusion is probably risky since the nucleophilicities of the solvents implied in (22)-(25) do not vary markedly. Data in non-nucleophilic fluorinated solvents would therefore help to fill the gap in our knowledge. 

Fig. 2.11.1. General structural formula of (I) primary alkyl sulfonates (PAS) and (II) secondary alkyl sulfonates (SASs).

Detergents, which now rival soap in demand, are based largely on petroleum the variety of structures which confer detergent properties have led to some interesting syntheses. Alkyl aryl sulfonates are made by alkylation of benzene either with chlorinated kerosene or with a highly-branched olefin made from propylene. Long chain olefins for secondary sulfates were made from paraffin wax. Secondary alkyl sulfonates were made by direct sulfonation of paraffins with sulfur dioxide and chlorine, a reaction discovered in America in the 193O s. 

DMAP has an ameliorating effect on the displacement of secondary alkyl sulfonates with inversion of configuration that employs CsOAc. ... 

Alkynes. These reagents undergo clean coupling with tertiary alkyl halides or secondary alkyl sulfonates. ... 

Description. Three major types of alkyl sulfonate must be considered the primary and secondary paraffin sulfonates (PS and SAS) and the a-olefin sulfonates (AOS). The secondary alkyl sulfonates (SAS) are exploited on a larger scale than primary paraffin sulfonates (PS). 

In 1992, Julia et al. [147] employed halomethylmagnesium halides [148] instead of halomethyl starmanes. This process allows the replacement of the sulfonyl group of primary and secondary alkyl sulfones by methylene and alkylidene chains with great success (Table 3.14). 

Esters. Most acryhc acid is used in the form of its methyl, ethyl, and butyl esters. Specialty monomeric esters with a hydroxyl, amino, or other functional group are used to provide adhesion, latent cross-linking capabihty, or different solubihty characteristics. The principal routes to esters are direct esterification with alcohols in the presence of a strong acid catalyst such as sulfuric acid, a soluble sulfonic acid, or sulfonic acid resins addition to alkylene oxides to give hydroxyalkyl acryhc esters and addition to the double bond of olefins in the presence of strong acid catalyst (19,20) to give ethyl or secondary alkyl acrylates. 

Primary and secondary alkyl haUdes and sulfonates react with potassium superoxide to form dialkyl peroxides (101,102) (eq. 28). Dia2oalkanes, eg, dia2omethane, have been used to alkylate hydroperoxides (66) (eq. 29). 

Scandium triflate and lanthanide triflates also catalyze alkylation by secondary methane-sulfonates. ... 

Thiols, the sulfur analogs of alcohols, are usually prepared by Sjv 2 reaction of an alkyl halide with thiourea. Mild oxidation of a thiol yields a disulfide, and mild reduction of a disulfide gives back the thiol. Sulfides, the sulfur analogs of ethers, are prepared by an Sk2 reaction between a thiolate anion and a primary or secondary alkyl halide. Sulfides are much more nucleophilic than ethers and can be oxidized to sulfoxides and to sulfones. Sulfides can also be alkylated by reaction with a primary alkyl halide to yield sulfonium ions. 

Trifluoromethanesulfonates of alkyl and allylic alcohols can be prepared by reaction with trifluoromethanesulfonic anhydride in halogenated solvents in the presence of pyridine.3 Since the preparation of sulfonate esters does not disturb the C—O bond, problems of rearrangement or racemization do not arise in the ester formation step. However, sensitive sulfonate esters, such as allylic systems, may be subject to reversible ionization reactions, so appropriate precautions must be taken to ensure structural and stereochemical integrity. Tertiary alkyl sulfonates are neither as easily prepared nor as stable as those from primary and secondary alcohols. Under the standard preparative conditions, tertiary alcohols are likely to be converted to the corresponding alkene. 

The reaction of alkyl halides with metal nitrites is one of the most important methods for the preparation of nitroalkanes. As a metal nitrite, silver nitrite (Victor-Meyer reaction), potassium nitrite, or sodium nitrite (Kornblum reaction) have been frequently used. The products are usually a mixture of nitroalkanes and alkyl nitrites, which are readily separated by distillation (Eq. 2.47). The synthesis of nitro compounds by this process is well documented in the reviews, and some typical cases are listed in Table 2.3.92a Primary and secondary alkyl iodides and bromides as well as sulfonate esters give the corresponding nitro compounds in 50-70% yields on treatment with NaN02 in DMF or DMSO. Some of them are described precisely in vol 4 of Organic Synthesis. For example, 1,4-dinitrobutane is prepared in 41 -46% yield by the reaction of 1,4-diiodobutane with silver nitrite in diethyl ether.92b 1-Nitrooctane is prepared by the reaction with silver nitrite in 75-80% yield. The reaction of silver nitrite with secondary halides gives yields of nitroalkanes of about 15%, whereas with tertiary halides the yields are 0-5%.92c Ethyl a-nitrobutyrate is prepared by the reaction of ethyl a-bromobutyrate in 68-75% yield with sodium nitrite in DMF.92d Sodium nitrite is considerably more soluble in DMSO than in DMF as a consequence, with DMSO, much more concentrated solutions can be employed and this makes shorter reaction times possible.926... 

Secondary alkane sulfonates (SASs), alkyl sulfates (ASs) and alkylether sulfates (AESs)... 

At the end of the 1990s statistics show that the non-ionic surfactants achieved the highest growth in production rates world-wide, though anionic surfactants (anionics) maintained the dominant position in the surfactant market. Today they are produced in a larger variety by the petrochemical industry than all other types of surfactants. Their production spectrum covers alkyl sulfates (ASs), secondary alkane sulfonates (SASs) and aryl sulfonates and carboxylates via derivatives of partly fluorinated or perfluorinated alkyl surfactants to compounds with an alkylpolyglycolether substructure combined with an anionic moiety such as alkylether sulfates (AESs), phosphates, phosphonates or carboxylates. 

As a direct result of the smdies on the separation of sulfonates, Zheng et al. [67] showed that secondary amines and quaternary ammonium salts could be separated using a cyanophase column using sodium alkyl sulfonate additives in methanol/C02 mixtures with 30 0% methanol in the mixture. Ion-pairing was thought to be the retention mechanism responsible for the separation. 

Alkylation of hydroxylamines with secondary alkyl halides and alkyl sulfonates like 10 (equation 7) is one of the most frequently used synthetic approaches, especially to enantiomerically pure hydroxylamines such as 11 (equation 7). The reaction proceeds with inversion of configuration and does not produce appreciable amounts of diaUcyla-tion products. Both hydroxylamine as well as N- and O-alkylhydroxylamines have been successfully used. Alkyl trillates are probably the most useful substrates for these transformations since they can be prepared from a large pool of commercially available enantiomerically pure chiral secondary alcohols. 

Salts of sulfonic acids can be prepared by treatment of primary or secondary alkyl halides with sulfite ion,799 Even tertiary halides have been used, though the yields are low. Epoxides treated with bisulfite give 3-hydroxy sulfonic acids. ... 

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