Arenes sulfurization

Science dealerships aren t the only places to get the stuff one needs. At those mega hardware stores one can find pure acetone, methanol, ethanol, toluene, methyl ethyl ketone, DCM(as a constituent of some stripping agents), sodium hydroxide in the form of lye, and some acids such as sulfuric and hydrochloric. These precious tools can be bought there cheaply and in great quantity. 

Sulfonation (Section 12 4) Sulfonic acids are formed when aromatic compounds are treated with sources of sulfur trioxide These sources can be concentrated sulfuric acid (for very reactive arenes) or solutions of sulfur trioxide in sulfuric acid (for ben zene and arenes less reactive than ben zene)... 

Sulfonic acids are prone to reduction with iodine [7553-56-2] in the presence of triphenylphosphine [603-35-0] to produce the corresponding iodides. This type of reduction is also facile with alkyl sulfonates (16). Aromatic sulfonic acids may also be reduced electrochemicaHy to give the parent arene. However, sulfonic acids, when reduced with iodine and phosphoms [7723-14-0] produce thiols (qv). Amination of sulfonates has also been reported, in which the carbon—sulfur bond is cleaved (17). Ortho-Hthiation of sulfonic acid lithium salts has proven to be a useful technique for organic syntheses, but has Httie commercial importance. Optically active sulfonates have been used in asymmetric syntheses to selectively O-alkylate alcohols and phenols, typically on a laboratory scale. Aromatic sulfonates are cleaved, ie, desulfonated, by uv radiation to give the parent aromatic compound and a coupling product of the aromatic compound, as shown, where Ar represents an aryl group (18). 

Tnfluoroacetic anhydnde in a mixture with sulfuric acid is an efficient reagent for the sulfonylation of aromatic compounds [44] The reaction of benzene with this system in nitromethane at room temperature gives diphenyl sulfone in 61% yield Alkyl and alkoxy benzenes under similar conditions form the corresponding diaryl sulfones in almost quantitative yield, whereas yields of sulfones from deactivated arenes such as chlorobenzene are substantially lower [44] The same reagent (tnfluoroacetic anhydride-sulfunc acid) reacts with adamantane and its derivatives with formation of isomeric adamantanols, adamantanones, and cyclic sultones [45]... 

The photolysis of 10.3a in pentane or the reaction of 10.3a with PPhs generate the corresponding sulfur diimide ArN=S=NAr (Ar = 2,4- Bu2-6-MeC6H2) as the major product, presumably via the intermediate formation of the thionitrosoarene." By contrast, thermolysis in arene solvents results in ring closure to give the 2,1-benzisothiazole 10.4 and the corresponding aniline."... 

Thiepin, as a seven-membered conjugated system with sulfur as heteroatom, is a member of the 8 7t-electron heteroannulenes which are antiaroinatic according to Hiickel s rule. In contrast to oxepin, thiepin is not stable at room temperature and no valence isomerism with an arene sulfide has been observed. Stable thiepins are obtained only when two bulky substituents, e.g. /ert-butyl, are introduced into positions 2 and 7. In benzothiepins the annellation effect of the aromatic rings contributes decisively to the stability of these compounds stability increases with an increasing number of fused benzene rings. 

BromophenyI Enynes with Initiation by tert-RutyUithium and Sulfur (Fragments Arene C=C C = C and S)... 

Duffield and coworkers65 studied the El- induced mass spectra of five arene- (215-219) and four alkane sulfonylthioureas (220-223) and observed two rearrangement processes, namely loss of S02 from 215-219 and the elimination of ArS02 and RS02 with the thione sulfur atom from 215-223. The other fragmentations involved simple bond cleavages with and without hydrogen transfer (equation 48). The loss of H2S was evident for all the compounds studied except 221 and 222. It was, however, found to be a thermal and not an ionization process. 

Beside these free radical reactions of sulfur dioxide, its electrophilic reactions generating sulfinates with organometallic compounds453,454 or sulfinic acids with arenes under Friedel-Crafts conditions455 are well known. To complete these three-component syntheses, the sulfinates prepared first are transformed to sulfones by reactions with appropriate electrophiles, discussed earlier in this chapter, i.e. equation 82. 

It has been known472 that sulfones are side-products in the course of sulfonation of arenes with sulfur trioxide or its derivatives. Generally, this reaction may be expressed by equation 90. Mechanistic investigations have indicated473 that this reaction follows the pathway shown in equation 91. 

Abstract The photoinduced reactions of metal carbene complexes, particularly Group 6 Fischer carbenes, are comprehensively presented in this chapter with a complete listing of published examples. A majority of these processes involve CO insertion to produce species that have ketene-like reactivity. Cyclo addition reactions presented include reaction with imines to form /1-lactams, with alkenes to form cyclobutanones, with aldehydes to form /1-lactones, and with azoarenes to form diazetidinones. Photoinduced benzannulation processes are included. Reactions involving nucleophilic attack to form esters, amino acids, peptides, allenes, acylated arenes, and aza-Cope rearrangement products are detailed. A number of photoinduced reactions of carbenes do not involve CO insertion. These include reactions with sulfur ylides and sulfilimines, cyclopropanation, 1,3-dipolar cycloadditions, and acyl migrations. 

Although anaerobic desulfonation of arene sulfonates, in which the sulfonate is used as a source of sulfur, has been described in a Clostridium sp., the product was not identified (Denger et al. 1996,... 

Benzene and naphthalene compounds can be formylated under Vil-smeir conditions. The formyl compounds, with or without isolating, can be condensed with amino arenes to give leuco compounds. In this reaction, the benzhydrol intermediate is not isolated.21,79,84 86 The reaction is generally carried out in an alcohol solvent such as isopropanol, butanol, or pentanol and an acid catalyst such as hydrochloric acid, sulfuric acid, or methanesul-fonic acid.87 Acetic acid can also be used both as catalyst and as the solvent. Urea sometimes is added as catalyst.84,88 Terephthaldehyde reacts with W-diethyl-3-methylaniline89 and substituted azulenes to give a bis-triphenylmethane21 57 and 58, respectively. 

Longer Hg-7r interactions are observed in the /> ra-/-butylcalix[4]arene mercury complex 162. The mercury atom forms primary bonds with the two sulfur atoms and engages in weaker secondary interactions with two arene rings of the calixarene whose centroids sit at 3.07-3.11 A from the metal center.201... 

In the former case, the dibromo- or dichloro-substituted arene is reacted with cuprous or sodium thiolates to give vicinal thioethers, which can be reductively dealkylated, for example with Na/NH3, to give the dithiols.63 Alternatively, benzenethiol is reacted with ra-BuLi, and the resulting lithiated product is made to react with elemental sulfur to give the 1,2-dithiolate salt. 

---