Sulfonyl with alcohols

The chloride of triflic acid (trifluoromethanesulfonyl chloride) is an effective sulfonylating agent Like triflic anhydride, it usually reacts with alcohols and other nucleophiles with the formation of the corresponding derivatives of tnflic acid [69] However, in some reactions, it acts as a chlorinating reagent [98] The reactions of tnfluoromethanesulfonyl chloride with 1,3-dicarbonyl compounds or some carboxylic esters in the presence of a base result m the formation of chlonnated products in high yields (equation 49)... 

A sulfonyl chloride group rapidly reacts with amines in the pH range of 9-10 to form stable sulfonamide bonds. Under these conditions, it also may react with tyrosine —OH groups, aliphatic alcohols, thiols, and histidine side chains. Conjugates of sulfonyl chlorides with sulf-hydryls and imidazole rings are unstable, while esters formed with alcohols are subject to nucleophilic displacement (Nillson and Mosbach, 1984 Scouten and Van der Tweel, 1984). The only stable derivative with proteins therefore is the sulfonamide, formed by reaction with e-lysine... 

The most common synthesis of sulfonic esters, which can also be conducted on insoluble supports, is the sulfonylation of alcohols with sulfonyl chlorides under basic reaction conditions. Several examples of the sulfonylation of support-bound alcohols and of the reaction of support-bound sulfonyl chlorides with alcohols have been reported (Table 8.11). For the preparation of highly reactive sulfonates, bases of low nucleophilicity, such as DIPEA or 2,6-lutidine, should be used to prevent alkylation of the base by the newly formed sulfonate. This potential side reaction is, however, less likely to occur on cross-linked polystyrene than in solution, because quaternization on hydrophobic supports only proceeds sluggishly (see Section 10.2 and [155]). 

Sulfonimidothiazolines, 317, 318 Sulfonyl halides, with 2-aminothiazoles, 69 Sulfur (Sg), in synthesis of, A-4-thiazoline-2-thione, 373 Sulfur compounds, 69 Sulfuric acid, with alcohols, 38, 47, 80, 90 in bromination, 77 dealkylation by, 39 deuterated, 92 diazotization with, 66 in nitrations, 72 rearrangements in, 73, 113 Sulfuryl chloride, 432 Symbiotic behavior, see HSAB theory Symmetry. C2v and C2p, 120 Synthetic fibers, 154... 

For primary and secondary alcohols, the hydroxyl is best made into a leaving group for elimination reactions by sulfonylation with toluene-para-sulfonyl chloride (tosyl chloride, TsCl) or methanesulfonyI (mesyl chloride, MeS02Cl orMsCl). 

Methanesulfonyl chloride may be a new reagent to you. In the presence of a base (usually triethy-lamine, EtjN) it reacts with alcohols to give methanesulfonate esters, but the mechanism differs from the mechanism with TsCl. The first step is an elimination of HC1 from the sulfonyl chloride (this can t happen with TsCl, because there are no available protons) to give a sulfene. The sulfene is highly electrophilic at sulfur, and will react with any alcohol (including tertiary alcohols, which react very slowly with TsCl). Here are the two mechanisms compared, formation of toluenesuifonates (tosylates) reagents ROH + TsCl + pyridine... 

The reaction between sulfonyl chlorides and cycloalkanone oximes in the presence of pyridine is followed by Beckmann rearrangement to the imidochlorides, which give the corresponding lactim ethers with alcohol.58... 

Sulfonic esters are most frequently prepared by treatment of the corresponding sulfonyl halides with alcohols in the presence of a base. This procedure is the most common method for the conversion of alcohols to tosylates, brosylates, and similar sulfonic esters. Both R and R may be alkyl or aryl. The base is often pyridine, which functions as a nucleophilic catalyst, as in the similar alcoholysis of carboxylic acyl halides (16-61). Propylenediamines have also been used to facilitate tosylation of an alcohol. Silver oxide has been used, in conjunction with KI. Primary alcohols react the most rapidly, and it is often possible to sulfonate selectively a primary OH group in a molecule that also contains secondary or tertiary OH groups. The reaction with sulfonamides has been much less frequently used and is limited to A,A-disubstituted sulfonamides that is, R— may not be hydrogen. However, within these limits it is a useful reaction. The nucleophile in this case is actually RO . However, R may be hydrogen (as well as alkyl) if the nucleophile is a phenol, so that the product is RS020Ar. Acidic catalysts are used in this case. Sulfonic acids have been converted directly to sulfonates by treatment with triethyl or trimethyl orthoformate, HC(OR)3, without catalyst or solvent and with a trialkyl phosphite, P(OR)3. ... 

The conversion of the sulfonyl chloride to the sulfonyl fluoride was carried out as follows. The sulfonyl chloride was removed from the filter by washing it with alcohol-free chloroform into a 5-ml round-bottom flask. The chloroform was then removed and 0.5 ml of acetonitrile and 167 mg of dry powdered sodium fluoride was added. The resulting mixture was magnetically stirred at 90°C for 6 hr, 2 ml of alcohol-free chloroform was then added and the mixture was filtered into a sublimation apparatus and the solvent was removed in a stream of nitrogen. The product sublimed readily at 45°C (0.3 mm) and could then be recrystallized from benzene-cyclohexane to yield crystals with m.p. 90-92°C. 

The reagent reacts with alcohols and phenols to give urethane-N-sulfonyl chlorides, which are hydrolyzed by water to carbamates. It reacts with an olefin to give either a... 

One of die most popular reactions in organic chemistry is dissolving metal reductions [1-3], Two systems are frequently used - sodium dissolved in ammonia with alcohol and lithium dissolved in alkylamines [4]. Although calcium is seldom used, it has been successfully applied to the reduction of a variety of compounds and functional groups [5], including aromatic hydrocarbons, carbon-carbon double and triple bonds, benzyl ethers, allyl ethers, epoxides, esters, aliphatic nitriles, dithianes, als well as thiophenyl and sulfonyl groups. 

Boranes other than those based on a-pinene are particularly useful in allylic transfer to imines to make single enantiomers of unsaturated amines. One good combination is an allylboron compound 80 complexed with an /V-sulfonyl amino alcohol such as 78, derived from nor-ephedrine (see chapter 23) with an /V-silyl imine such as 81. The unsaturated amines 82 are formed in good... 

The typical ring-opening reaction with alcohols, either neat,66 or in the presence of bases such as sodium alkoxide51 or triethylamine,50 leads to the corresponding iV-[(2-sulfanylphenyl)-sulfonyl]carbamates 1. 

Such uncatalyzed solvolytic processes are synthetically unimportant as a procedure for making esters, for example, the reaction is usually highly inefficient because of the tendency of these esters to alkylate an alcohol about as fast as the sulfonyl chloride sulfonylates an alcohol, and so by the time the starting material is consumed, extensive further reaction of the product will have occurred. On the other hand, the promotion of esterification by tertiary amines is a routine synthetic procedure with both arenesulfonyl and alkanesulfonyl species. 

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