Sulfides, diaryl synthesis

Unsymmetrical diaryl sulfides (60 R = 2-NO2, 4-NO2, 2,4-(N02)2 R = H, 4-NMe2) were obtained in 80-97% yields from the reaction under PTC conditions of nitro-activated aryl halides with arenethiolates generated in situ from the reduction of the corresponding diaryl disulfides with aminoiminomethanesul-finic acid (61).192 Arylthiolates carrying electron-withdrawing substituents were not sufficiently reactive. The reaction could also be applied to the synthesis of diaryl selenides, but not of ditellurides. 

Thiation of aromatic compounds is utilized both for the preparation of aryl sulfides and for the generation of sulfur heteroarenes. The diaryl thioether motif is found in the structure of several approved pharmaceuticals, such as antihistamines. In a recent letter, Wu and He disclosed that Cu(I) catalysis is very efficient for the coupling of thiophenols with aryl iodides (Scheme 39) [ 108]. The procedure is very similiar to the diaryl ether synthesis under microwave irradiation reported by the same authors. 

An intramolecular Heck-carbonylation/cyclization of the vinyl iodide 881 provides the 5,6-dihydropyran-2-one 882 during a total synthesis of manoalide (Equation 354) <1997CC1139>. The reaction of but-3-yn-l-ol with diaryl sulfides and carbon monoxide in the presence of a palladium(O) catalyst leads to a novel thiolactonization and hence arylthiosubstituted 5,6-dihydropyran-2-one 883 (Equation 355). Similar results are obtained with diaryl diselenides (Equation 355) <1997JOC8361>. Hydrozirconation of O-protected homopropargylic alcohols followed by carbonyla-tion and quenching with iodine provides a simple route to 5,6-dihydropyran-2-ones <1998TA949>. 

Thermal reaction of potassium trifluoroacetate with diaryl disulfides 30 is a useful method for effecting the synthesis of aryl trifluoromethyl sulfides 31 (see Table 3), ... 

Abbady MA, Hebbachy R (1993) Synthesis and application of some symmetrical and unsymmetrical diaryl sulfides and diaryl sulfones containing pyrazolinyl and isoxazolinyl moieties. Indian J Chem Sect B 32 1119-1124... 

The majority of syntheses of 1,4-thiazines involve the elimination of HL from species of type 11. Precursors of type 11a are not usually isolable compounds but are generated as intermediates. Two methods for the formation of such intermediates have been described one utilizes tetrahydro-1,4-thiazine-3,5-diones as starting materials, and the other requires diacyl sulfides and ammonia. Thus the synthesis of 2/f-l,4-thiazine (6), reported in 1948, was achieved by heating compound 16 at 450°C in the presence of powdered aluminum. Potentially, the procedure may be applied to the preparation of thiazines variously substituted at positions 2 and 6 however, the low yield (13%) achieved for the parent compound is a detraction. It was initially claimed that the reaction of diphenacyl sulfide with ammonia gave 3,5-diphenyl-4H-l,4-thiazine subsequent studies, however, revealed that the product was the 2//-tautomer 3,5-Diaryl-2/f-l,4-thiazines and... 

The synthesis of 1,2/C-a/aphosphospholancs 127 is based on the reaction of the substituted 3-aminopropylphosphines with diaryl disulfides or with elemental bromine in the presence of triethylamine [171, 172] (Scheme 77). Furthermore, the cyclic P(III) compounds may be converted to the corresponding oxides 122 or sulfides 128, useful as lubricating oil antioxidants and flame retardants in plastics and textiles. 

As base. Numerous reactions that are initiated by deprotonation have been conducted with KF-AI2O3. These include the synthesis of diaryl ethers, amines, and sulfides by nucleophilic aromatic substitutions, AJ-alkylation of 2,4-dinitrophenyl-hydrazones, condensation of 3-phenylisoxazol-5-one with aldehydes, and ring closure of /V-(w-chloroalkyl) carboxamides to afford 1,3-oxazolines and 1,3-oxazines. ... 

A high yield synthesis of diaryl ethers involves nucleophilic attack by phenoxide on arynes generated from iodobenzenes. The arynic nature was established with substituted iodobenzenes ( -MePhI and phenol, for example, gave 35% m-tolyl phenyl ether as well as 25% of t -tolyl phenyl ether). Diaryl sulfides were similarly prepared from thiophenols and iodoarenes. 

Several examples of S-arylation of sulfides and P-arylation of phosphines using diaryliodonium salts were reported in the older literature [877,878]. These reactions generally proceed by a radical chain mechanism. The arylation of phosphines has been used to promote the photo-initiation of cationic polymerization [879]. More recently, the synthesis of diaryl sulfones via S-arylation of sodium arenesulfinates, ArS02Na, by diaryliodonium salts has been reported [880]. 

A mild protocol for the synthesis of diaryl and heteroaryl sulfides has been developed. Biological studies have identified promising inhibitors of MCF-7 breast cancer cell proliferation such as oxadiazole derivative 197 (14JOC1947). 

Swapna, K., Murthy, S. N., Jyothi, M. T., and Nageswar, Y. V. D. 2011. Nano-CuFe204 as a magnetically separable and reusable catalyst for the synthesis of diaryl/aryl alkyl sulfides via cross-coupling process under ligand-free conditions. Org. Biomol. Chem. 9(17) 5989-5996. 

Diels-Alder reaction of alkynyl sulfides followed by oxidation has been used for the synthesis of diaryl sulfides (Scheme 16.22) [23]. 

An equimolar amount of 30%-H2O2 added dropwise with stirring to phenyl vinyl sulfide in acetic anhydride, stirring continued 5-6 hrs., and allowed to stand overnight phenyl vinyl sulfoxide. Y 82%. F. e. s. A. V. Sviridova, V. I. Laba, and E. N. Prilezhaeva, Zh. Org. Khim. 7, 2480 (1971) C. A. 76, 72158 with N-chloro-nylon-66 in methanol-benzene or water-dioxane s. Y. Sato, N. Kunieda, and M. Kinoshita, Chem. Lett. 1972, 1023 (Eng) C. A. 77, 164179 with ammonium cerium(IV) nitrate, mostly diaryl sulfoxides, s. T.-L. Ho and C. M. Wong, Synthesis 1972, 561. 

Figure 2.11 A cross-section of results for the Pd-catalyzed synthesis of unsymmetrical and symmetrical diaryl sulfides with potassium thioacetate, as reported by Park et al. [52],...

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