S-Arylation

The second method is based on the optically active enamine formed from (S)-prolinol methyl ether and cyclohexanone. This enamine reacts spontaneously with 2-(arylmethylcnc)propane-dioates to give, after hydrolysis, the 2- (.S )-aryl[(,S )-2-oxocyclohexyllmethyl propanedioates 4 in 35-76% yield with d.r. 94 6 > 97 361. 

S-aryl), concomitant sulfoxidation can be observed and the diastereoselectivity relative to the cis-diol depends on the nature of the sulfur substituents [239]. 

Hollingworth RM, Alstott RL, Litzenberg RD. 1973. Glutathione-S-aryl transferase in the metabolism of parathion and its analogs. Life Sci 13 191 -199. 

Fig. 3i-iii. Dendrimer synthesis using branched building blocks i Denkewalter s polylysine dendrimers ii Newkome s polyamide dendrimers iii Frechet s aryl ether dendrimers... 

Intramolecular palladium catalyzed thio-enolate S-arylation has been used in a route to a set of fused benzo[ ]thiophenes, as illustrated by the conversion of the substrate 10 into the product 11 <06T11513>. 

Microwaves were used to support S-arylation of 5-substituted oxadiazoline-2-thiones <2000BMC69> and <2000M1207>. 5-(4-Pyridyl)oxadiazoline-2-thiones treated with 2-haloesters also afforded A-alkyl derivatives <2000CHE851>. A similar reaction occurred in the case of 5-pyrazolyloxadiazoline-2-thiones <2000JFA5312>. Organophosphorus derivatives of 1,3,4-oxadiazole were obtained by the reaction of bis(oxadiazolinethiones) with 0,0-diethylchlorophosphate (Scheme 21) <1998JFA1609>. 

The carbon-nitrogen triple bond of aryl thiocyanates acts as a dipolarophile in 1,3-dipolar cycloadditions. Reactions with nitrile oxides yield 5-arylthio-1,2,4-oxadiazoles 227 (X = O Y = S). Aryl selenocyanates behave similarly forming 5-arylseleno-l,2,4-oxadiazoles 227 (X = 0 Y = Se). Reactions of 5-aryl-... 

Because anti/syn ratios in the product can be correlated to the E(0)/Z(0) ratio of the involved boron enolate mixture,10b initial experiments were aimed at the preparation of highly E(0)-enriched boron enolate. The E(0)/Z(0) ratio increases with the bulk of the alkanethiol moiety, whereas the formation of Z(O) enolates prevails with (S )-aryl thioates. (E/Z = 7 93 for benzenethiol and 5 95 for 2-naphthalene thiol esters). E(O) reagent can be formed almost exclusively by reaction of (5)-3,3-diethyl-3-pentyl propanethioate 64 with the chiral boron triflate. High reactivity toward aldehydes can be retained in spite of the apparent steric demand (Scheme 3-22).43... 

Polymer-supported synthesis of S-alkyl and S-aryl dithiocarbamates (Table 4.25)... 

The redox reaction shown in Scheme 7.60 results in the formation of an amide a-radical and tetrathiafulvalene cation-radical. These initially formed a-radical and cation-radical combine to give salts of the S-arylated tetrathiafulvalene (a minor product) and C-alkylated tetrathiafulvalene (the main product). The latter demonstrates an unprecedented carbon-carbon bond formation with the cation-radical of tetrathiafulvalene the structure depicted was confirmed by single crystal x-ray analysis (Begley et al. 1994). 

The procedure described is a good general method3 for obtaining a thiophenol from the respective phenol. It employs three steps conversion of a phenol to the O-aryl dialkylthiocarba-mate by treatment with dialkylthiocarbonyl chloride pyrolysis of the O-aryl dialkylthiocarbamate to the S-aryl dialkylthio-carbamate and hydrolysis of the latter to the aryl mercaptan. 

The immediate precursor of pentachlorothiophenol was assumed to be S-(PCP)Cys. Cysteine C-S lyase enzymes that convert S-aryl and S-alkyl derivatives of cysteine to pyruvate and a thioalcohol have been detected in some plant species (24,. When the... 

Pappalardo and co-workers studied the mass spectral characteristics of alkyl and aryl substituted 2,5-dithio-1,3,4-thiadiazoles. Selected ions in the mass spectra of SH, S-CH3, and S-aryl thiadiazoles were tabulated. The S-aryl thiadiazoles form stable cyclic ions yielding additional fragments. The fragmentation pattern is dependent on the structural characteristics of the substituents. If both tautomers—thiol and thione—are present, the molecular ion will also lose CS2. Besides the base peak, intense peaks observed in the MS spectrum are due to extensive fission of the thiadiazole ring. Some of the fragments formed are shown in Scheme 4 <820MS(17)335). 

Aryl-arylazo-sulfane reagieren mit 2-Hydroxy-naphthalin in alkalischem Ethanol zu Azo-Verbindungen. Die Reaktionen werden dutch elektronenliefernde Substituenten im N-Aryl-Teil erleichtert bzw. im S-Aryl-Teil erschwert1. 

Attack by Carbon. Preparation of Sulfones S- Aryl-de-chlorination... 

Photolysis of phenyl 2-thenoate leads to a 3 2 mixture of ortho and para Fries rearrangement products (Scheme 109) (74H(2)423). The photolytic rearrangement of a thiolester to a thiopyrone has been investigated with thiophenecarbothioic acid S-aryl esters as substrates (79LA2043). In the case of the 2-carbothioic acid esters, a 3-bromo substituent is necessary for this rearrangement. On the other hand, such a substituent is not necessary for the 3-carbothioic acid derivatives. In both cases, aldehydes may also be formed, sometimes as the main products (Scheme 110). 

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