SN2? catalysis and sulphene formation

Abstract

Ethenesulphonyl chloride reacts with a mixture of a tertiary amine and an alcohol by SN2' attack of the amine to form the positively charged sulphene which then gives a mixture of the ethenesulphonate and 2-trialkylammonioethanesulphonate esters.THE formation of alkyl ethenesulphonates (2) by the reaction of ethenesulphonyl chloride (1) with alcohols in the presence of a tertiary amine is apparently unreported, even though compounds (2) are made under similar conditions from 2-chloroethanesulphonyl chloride,' which is also known to give (1) readily with 2,6-lutidine., A recent r e p ~r t , ~ in fact, claims 70--80~0 yields of the betaine (Py+CH,CH,SO,-) from (1) and pyridine (Py) in methanol or ethanol. We report on our work on the products and the mechanism of the reaction of (1) with tertiary aniines and alcohols. The reaction (in CH,Cl, a t 25 OC, for example) was found to occur very rapidly to give a mixture of esters

Vinylogous nucleophilic catalysis. Tertiary amine promoted hydrolysis of 1-alkene-1-sulfonyl chlorides

“…The former description, though brief, appears to convey an unintended implication that the reaction is necessarily concerted, and we therefore now use the less connotative term "vinylogous nucleophilic catalysis". Our first experiments and communication (17) investigated esterification in nonpolar media, but subsequent work on the hydrolysis has provided a system which, because it is simpler in its chemistry and easier to study kinetically, now appears to be the logical starting point for a detailed presentation of the mechanism of the reaction; the esterification reactions will be discussed in a subsequent paper.…”

“…As we show in this paper, the simple tertiary amine-promoted hydrolysis of ethenesulfonyl chloride does, in fact, proceed by a "path 6" mechanism. In preliminary communications (17,18) we have already outlined this and a related study of the corresponding reaction with alcohols in a nonpolar medium, and used the terms "SN2' catalysis" and "vinylogous nucleophilic catalysis" for the "path b" process. The former description, though brief, appears to convey an unintended implication that the reaction is necessarily concerted, and we therefore now use the less connotative term "vinylogous nucleophilic catalysis".…”

“…Finally, we recall that in our communications (17,18) we pointed to the likelihood that vinylogous nucleophilic catalysis would show up in other systems, and we are gratified to note that this prediction would appear to have been fulfilled for the a,P-unsaturated carbonyl system by the reports of lnoue and Bruice (50, 51) describing their work on what they term an "extended E l c B mechanism" in the hydrolysis of p-nitrophenyl 2-cyano-3-(p-methoxypheny1)propenoate." These authors, in addition to reporting their own studies, comment on the mechanism of the formation of the sulfene (16), stating that they "believe that this reaction also proceeds by the stepwise mechanism as is shown in this paper (i.e.…”

Vinylogous nucleophilic catalysis. The tertiary amine promoted reaction of ethenesulfonyl chloride with alcohols

“…In addition, Truce and Campbell (8) had looked at the action of triethylamine and alcohols on 1 -propene-1 -sulfonyl chloride and had noted the formation of both the 1 -propene-and 2-propenesulfonate esters, CH3CH=CHS020R and CH2= CHCH2S020R. In our first experiments (13), simple mixing of 1 with 2-propanol in the presence of pyridine or trimethylamine followed by conventional work-up gave the ethenesulfonate ester (5, R = Pri) in mediocre (40-50%) yield. To find out what had happened to the rest of the material, we examined the product directly by 'Hrnr, which showed the presence of about 60% of the ester (5, R = Pri) along with another product (-40%), which appeared to be Me3N+CH2CH2S020Pri C1-(6), i.e.…”

“…This last process was unknown at the time, but we have subsequently shown that this can be the chief route of the tertiary amine promoted hydrolysis of 1-alkenesulfonyl chlorides (1 1, 12). The present paper describes extension of this work to the reaction of alcohols with tertiary amines and 1-alkenesulfonyl chlorides; a preliminary report of the earliest stages has appeared (13).…”