Of sulfonyl chlorides

The sulfonyl chloride group is the cure site for CSM and determines the rate and state of cure along with the compound recipe. It is less stable than the Cl groups and therefore often determines the ceiling temperature for processing. The optimum level of sulfonyl chloride to provide a balance of cured properties and processibiUty is about 2 mol % or 1—1.5 wt % sulfur at 35% Cl. It also undergoes normal acid chloride reactions with amines, alcohols, etc, to make useful derivatives (17). 

Aliphatic sulfonyl chlorides that have a-hydrogen substituents, react with simple tertiary amines, such as trimethylamine, to generate sulfenes or perhaps their amine adducts 446). These species are suggested by the incorporation of one (but not more) deuterium atoms on reaction of sulfonyl chlorides with deuterated alcohols and triethylamine (447-450). A 2 1 adduct of sulfene and trimethylamine with proposed sulfonyl-sulfene structure could be isolated (451). 

The condensation of sulfonyl chlorides with enamines (452,453) derived from aldehydes and ketones has led to four-membered-ring sulfones, presumably through such intermediates (454-464). Open sulfonation products have also been obtained, particularly from ketone-derived enamines and from a-disubstituted sulfonyl chlorides. 

Conjugated dienamines were found to give predominantly double four-membered-ring adducts as well as a small amount of the six-membered-ring adduct (466,468). This important result indicates preferred attack at the terminal carbon of the dienamine system (in contrast to alkylation, for instance) in the generation of an initial zwitterionic intermediate. Addition of sulfonyl chloride and triethylamine to a homocyclic dienamine gave only the bridged product (446). 

Another point for structural diversification is the sulfonamide group. Imai had already shown that a wide variety of groups could be introduced at this position to optimize the reaction. Since a wide variety of sulfonyl chlorides are commercially available, a number of different types of groups could be examined (Scheme 3.34). Testing of a variety of aryl and alkyl groups on the 1,2-cyclohexanediamine backbone demonstrates that the simple methanesulfonamide 122 is clearly superior or equal to many other analogs in the cyclopropanation of cinnamyl alcohol (Table 3.11). Another concern which was directly addressed by this survey was the question of catalyst solubility. 

The drug can be prepared in a straightforward manner by reaction of sulfonyl chloride, 152, with di-n-propylamine fol-... 

The antiparasitic drug clorsulon (206), contains a rather unusual trichloroethylene group. This function is established early in the syntliesis by treatment of the perhalogenated compound 203 obtained from reduction of 202 with iron powder. Chlorosulfonation of 204 by means of chloro-sulfonic acid, followed by conver.sion of. sulfonyl chloride 205 to the amide, gives clorsulon (206) 153],... 

Sharpless and Klunder22 are developing a new procedure for conversion of sulfonyl chlorides directly into menthyl sulflnate esters using trimethyl phosphite as a reducing agent (equation 2). This method, starting with sulfonyl chlorides rather than with the much less available sulfinyl chlorides, should allow access to an even wider range of sulfinate esters and, ultimately, to various chiral, non-racemic sulfoxides. 

The copper-catalyzed additions of sulfonyl chlorides to conjugated dienes and trienes73 as well as to aryl-substituted cyclic olefins74 and substituted styrenes have been described75 for example, arenesulfonyl chlorides add to vinylarenes providing good to excellent yields75 of /J-chlorosulfones ... 

The three steps 32-34 have been suggested77 to be equilibria, and the overall equilibrium must lie far to the left because no adduct 23 is found in the reaction mixture when the reaction of sulfonyl chloride with olefin is carried out in the absence of a tertiary amine. A second possible mechanism involving oxidative addition of the arenesulfonyl halide to form a ruthenium(IV) complex and subsequent reductive elimination of the ruthenium complex hydrochloride, [HRulvCl], was considered to be much less likely. 

The treatment of sulfonyl chlorides with ammonia or amines is the usual way of preparing sulfonamides. Primary amines give N-alkyl sulfonamides, and secondary amines give N,N-dialkyl sulfonamides. The reaction is the basis of the Hinsberg test for distinguishing between primary, secondary, and tertiary amines. N-Alkyl sulfonamides, having an acidic hydrogen, are soluble in alkali, while N,N-dialkyl sulfon-... 

Sulfinic acids can be prepared by reduction of sulfonyl chlorides. Though mostly done on aromatic sulfonyl chlorides, the reaction has also been applied to alkyl compounds. Besides zinc, sodium sulfite, hydrazine, sodium sulfide, and other reducing agents have been used. For reduction of sulfonyl chlorides to thiols, see 19-57. 

As a consequence of facile homolytic cleavages, sulfonyl halides (I > Br > Cl F unsuitable) are able to add to unsaturated C—C systems. To prevent (or reduce) competing polymerizations, the additions of sulfonyl chlorides have been recommended to be carried out in the presence of copper(I/II) salts (Asscher-Vofsi reaction ). Comprehensive surveys have been published on the resulting j8-halogeno sulfones (or their vinyloguous compounds) as well as on their dehalogenation products (vinyl sulfones, 1-sulfonyl-l, 3-dienes, etc.). Table 5 reviews a series of sulfonyl halide additions and facile hydrogen halide eliminations. 

Indium-mediated coupling of sulfonyl chlorides with alkyl bromides in water readily generates sulfones.89 Sulfones can also be obtained via... 

On use of N,N -dicyclohexylcarbodiimide instead of sulfonyl chlorides as condensation reagent in oligonucleotide synthesis, then the pyro-, tri- and tetraphosphate stages are again involved 124). The metaphosphate 183 a is found in small amounts by 3iP-NMR spectroscopy, but again no cyclic trimetaphosphate 184 can be detected, which would also be a possible phosphorylation reagent. 

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... 

H NMR spectrum indicates that the crude product is comprised of a mixture of the sulfonyl chloride 2 and the sulfonic anhydride in an 11 1 ratio. Pure sulfonyl chloride 2 is obtained by distillation. Alternatively, the crude sulfonyl chloride can be chromatographed (60 g of silica gel per 1 g of sulfonyl chloride) eluting with hexane to provide pure 2 in equivalent yields. 

More abundant are reductions with sodium sulfite which is applied in aqueous solutions (solubility 24%). Its specialties are reduction of peroxides to alcohols [257], of sulfonyl chlorides to sulfinic acids [252], of aromatic diazonium compounds to hydrazines [253], and partial reduction of geminal polyhalides [254] Procedure 43, p. 216). 

Complete reduction of sulfonyl chlorides to thiols can be achieved by lithium aluminum hydride [680,693], with zinc [696] and with hydriodic acid generated in situ from iodine and red phosphorus [230]. m-Nitrobenzenesulfonyl chloride, however, was reduced not to the thiol but to bis(m-nitrophenyl)disulfide by hydriodic acid in 86-91% yield [697]. 

To explain the difficulties encountered in the reuse of sulfonyl chloride functionalized ionic liquids during Beckmann rearrangement, Deng and colleagues proposed a mechanism for rearrangement of cyclohexanone oxime (equation 97). 

The most direct approach to the four-membered S-ring is cycloaddition of sulfenes to alkenes. The sulfenes are generated in situ by base-induced de-hydrohalogenation of sulfonyl chlorides. Because of their special susceptibility to cycloaddition reactions, research into the chemistry of sulfenes is expanding. 

Much research has been done on the synthesis of perhalogenated P-sultones. The sulfonation of acyclic fluorovinyl ethers leads to a product that is stable up to slightly above room temperature. Thermolysis decomposes the ring structure under SO2 evolution and formation of acid fluorides and perfluorocyclopropane (Eq. 78). )S-Sultones have been synthesized by addition of sulfonyl chlorides to perhalogenated ketones in the presence of triethylamine. The formation of the l-oxa-2-thiacyclobutane 2,2-dioxides appears to require an activated but sterically unhindered carbonyl group because acetone, chloroacetone, trifluoroacetophenone, and p-nitroaceto-phenone did not yield the desired products. ... 

Fused A -sulfonylketenimine 102 has been synthesized upon treatment of sulfonyl chloride 199 with ammonia (Equation 29) <1998CJC164>. 

---