Regioselective synthesis of quinolone-annulated sulfur heterocycles by aryl radical cyclization

The tin hydride-mediated cyclizations of a number of sulfides and sulfones under mild, neutral conditions, have been investigated accompanied by some amount of β-scission product for sulfides. The sulfides were derived from 4-mercaptoquinolone and 2-bromobenzyl bromides by phase transfer catalyzed reaction and the corresponding sulfones were prepared by treatment of the sulfides with m-CPBA at room temperature. The sulfides and the corresponding sulfones were then reacted with ⁿBu₃SnH-AIBN to give regioselective quinolone-annulated sulfur heterocycles.     

Reaction of dichlorocarbene with vinyl sulfides

Conclusions The reaction of dihalocarbenes with vinyl sulfides gave gem-dihalocyclopropyl sulfides. The relative activity of the sulfides toward dichlorocarbene is 5–6 times greater than that of the corresponding ethers. The theory was expressed that intermediate sulfur ylides are formed in the given reaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1354–1358, June, 1980.     

Synthesis of furan from allenic sulfide derivatives

In this paper, we report the synthesis of furan derivatives from allenic sulfides. By the reaction with NaH, β-Hydroxyl allenic sulfides were found to generate furan products in excellent yields with the removal of phenylthio group. β-Aldehyde allenic sulfides were found to give similar furan products with one more substituent when treated with additional nucleophilic reagents. β-ketone allenic sulfides can also cyclize to give furan derivatives with the promotion of P₂O₅.     

Hemin-Promoted Direct C−H Thiolation in the Synthesis of Diaryl Sulfides

Diaryl sulfides are a class of important synthetic chemical units. Herein, we report a new method for direct preparation of diphenyl sulfides using P-toluenesulfonyl chloride as an effective thiophenyl radical precursor with assistance from Hemin. Various substituted anisoles and benzenesulfonyl chlorides are well tolerated, resulting in moderate to good yields of diaryl sulfides. The potential of the proposed method is validated by good yields obtained in gram scale reactions.     

Regioselective Synthesis of Benzofuran‐Annulated Six‐Membered Sulfur Heterocycles by Aryl Radical Cyclization

The tin hydride–mediated cyclization of a number of sulfides and sulfones under mild and neutral conditions has been investigated. The sulfides were in turn derived from 3(2H) benzothiofuranone and 2‐bromobenzyl bromides by phase‐transfer‐catalyzed reaction, and the corresponding sulfones were prepared by treatment of the corresponding sulfides with m‐CPBA at room temperature. The sulfides and sulfones were then reacted with ⁿ Bu₃SnH‐AIBN to afford regioselectively benzofuran‐annulated six‐membered sulfur heterocycles.     

Tantalum(V) or niobium(V) catalyzed oxidation of sulfides with 30% hydrogen peroxide

Tantalum(V) and niobium(V) are effective catalysts for the oxidation of sulfides with 30% hydrogen peroxide. The reaction of sulfides with 30% hydrogen peroxide catalyzed by tantalum(V) chloride or niobium(V) chloride in acetonitrile, i-propanol or t-butanol selectively provided the corresponding sulfoxides in high yields. The corresponding sulfones are efficiently obtained from the reaction of sulfides with 30% hydrogen peroxide in methanol catalyzed by tantalum(V) or niobium(V).     

Rh(II)-catalyzed [2,3]-sigmatropic rearrangement of sulfur ylides derived from N-tosylhydrazones and sulfides

In this paper, Rh₂(OAc)₄-catalyzed [2,3]-sigmatropic rearrangement of sulfur ylides derived from N-tosylhydrazones and sulfides is reported. A series of tosylhydrazones derived from aldehydes were successfully used for [2,3]-sigmatropic rearrangement by reaction with either allylic phenyl sulfides or propargyl phenyl sulfides. The reaction conditions were optimized and afforded the products in moderate to good yields. In addition, a novel and convenient approach for the synthesis of cyclobutenones and cyclopropanes has been developed through direct oxidation of the rearrangement products.     

Reactivity of cyclic sulfides in reactions with quinones

Sulfonium salts are obtained by the reaction of cyclic sulfides with 1,4-benzoquinone and 5,8-quinolinedione in an acidic medium. It is shown by the method of concurrent reactions that the introduction of alkyl substituents into molecules of thiacyclopentane and thiacyclohexane decreases the reactivity of the sulfides. Quinolinedione is less reactive towards sulfides than is benzoquinone.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 891–894, July, 1986.     

Investigation of Nitrogen- and Sulfur-containing Heterocycles. 53. Reactions of 5-Amino-6-mercaptopyrimidines with Derivatives of p-Chloronitrobenzene. Synthesis of a New Heterocyclic System - Pyrimido[4,5-b]-1,4-benzothiazepine

A series of pyrimidyl aryl sulfides was obtained from the reaction of 5-amino-6-mercaptopyrimidines with derivatives of p-chloronitrobenzene containing carbonyl functional groups. The properties of these sulfides and methods of their cyclization into derivatives of a new tricylic system, pyrimido[4,5-b]-1,4-benzothiazepine, were studied.     

Oxidations catalyzed by phenylacetone monooxygenase from Thermobifida fusca

Several organic sulfides, ketones and other organic systems have been tested as substrates in oxidation reactions catalyzed by the recently discovered phenylacetone monooxygenase from Thermobifida fusca. The biocatalytic properties of this Baeyer–Villiger monooxygenase have been studied, revealing reactivity with a large range of sulfides and ketones. Oxidations of several sulfoxides, an amine and an organoboron compound were also observed. The enzyme is able to oxidize a number of sulfides with excellent enantioselectivity, demonstrating the catalytic potential of this novel biocatalyst.     

Direct transformation of organosulfur compounds to organophosphorus compounds: rhodium-catalyzed synthesis of 1-alkynylphosphine sulfides and acylphosphine sulfides

A rhodium-catalyzed method for the synthesis of organophosphorus compounds directly from organosulfur compounds was developed. In the presence of RhH(PPh₃)₄ and depe, the reaction of 1-alkylthioalkynes with tetraethyldiphosphine disulfide gave 1-alkynylphosphine sulfides. The same complex catalyzed the reaction of thioesters giving acylphosphine sulfides.     

Reactions of azirines with sulfur nucleophiles. 4. Treatment of 2H-azirine with mercaptosubstituted acids. reactions of aziridinyl alkyl sulfides with carboxylic acids and acyl chloride derivatives

Treatment of 2H-azirines with mercaptosubstituted acids and their derivatives leads to -ketoamides and 2-aziridinyl alkyl sulfides, respectively. 2-Aziridinyl alkyl sulfides, in turn, react with carboxylic acids to give -ketoamides and substituted ethanethiol derivatives. Acylation of 2-aziridinyl alkyl sulfides with acyl halides generates a variety of products, depending on the reaction conditions; either products derived from cleavage and isomerization of the aziridinyl ring or (1-acylaziridinyl-2) alkyl sulfides are obtained.For communication 3, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 206–211, February, 1986.     

A Convenient Synthesis of Vinyl Sulfides

tert-Alkyl sulfides, with an α-(1H-benzotriazol-1-yl) group 6 and 13 , are readily prepared from N-[(aryl-thio)methyl]-1H-benzotriazoles 3 and N-( 11 ), respectively, by reaction with BuLi and then with the appropriate electrophile. The tert-alkyl sulfides 6 and 13 are smoothly converted by BF₃. OEt₂ into vinyl sulfides 5, 7 or 12 , respectively, in satisfactory yields.     

Reaction of arylthiacyclanylsulfonium salts with nitrogen bases

When arylthiacyclanylsulfonium salts are heated with nitrogen bases the C-S bond of the heteroring undergoes quantitative cleavage and the base adds to form a C-N bond. These sulfonium salts react with ammonia or pyridine to give ammonioalkyl sulfides; amino sulfides and secondary amine salts are obtained with excess secondary amines. The described reaction is a new preparative method for the synthesis of amino sulfides and ammonioalkyl aryl sulfides.     

Preparation of bromodifluoromethyl sulfide and its conversion to trifluoromethyl sulfide

Bromodifluoromethyl sulfides are prepared by the reaction of mercaptides with CF₂BrX (x=Br,Cl). And treatment of bromodifluoromethyl sulfides with various inorganic fluorides produced trifluoromethyl sulfides.     

Synthesis of Sulfides by Reactions of 1,1-Dichloro-2-chloro-methylcyclopropane with S-Nucleophiles

1,1-Dichloro-2-chloromethylcyclopropane reacts with thiolates to give 2,2-dichlorocyclopropylmethyl sulfides via replacement of the side-chain chlorine atom. The resulting sulfides are readily oxidized to the corresponding sulfones.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 3, 2005, pp. 381–386.Original Russian Text Copyright © 2005 by Mikhed’kina, Nedel’ko, Prezhdo.     

Convenient stereoselective synthesis of 3-hydroxy-2-iodo-2(E)-alkenyl sulfides via iodohydroxylation of 1,2-allenyl sulfoxides in the presence of BnSH

The iodohydroxylation of 1,2-allenyl sulfoxides with I₂ in the presence of BnSH affords 3-hydroxy-2-iodo-2(E)-alkenyl sulfides in good yields and selectivities. The stereochemistry for the products of this transformation is opposite to what was obtained from the iodohydroxylation of 1,2-allenyl sulfides. Based on the results of some control experiment, a mechanism was proposed.     

THE REACTION OF ANHYDROUS HCI/CHLOROFORM WITH DIARYL SULFOXIDES

Abstract

The reaction of variously substituted diaryl sulfoxides with anhydrous HCl in chloroform was examined. The products ranged from the corresponding sulfides to mono- and dichlorinated sulfides and sulfoxides. The same reaction in the presence of phenol afforded primarily the corresponding sulfides accompanied by o- and p-chlorophenol. The latter reaction is an efficient means for deoxygenating diaryl sulfoxides. The mechanism of the reaction and the nature of the chlorinating species are discussed.     

Fe(NO3)3·9H2O-catalyzed aerobic oxidation of sulfi des to sulfoxides under mild conditions with the aid of trifl uoroethanol

Selective oxidation of sulfides to sulfoxides was successfully performed by employing readily available Fe(NO3)3·9H2O as the active catalyst with oxygen as the oxidant in 2,2,2-trifluoroethanol (TFE) without the formation of sulfones. Nitrate anion could play a crucial role in promoting the reaction due to the oxidation capacity under acidic media. High yields of sulfoxides were exclusively obtained from the corresponding sulfides. Furthermore, both aromatic and aliphatic sulfides gave moderate to high yields of sulfoxides with this protocol.     

Regioselective Synthesis of 1,8-Naphthyridinone-Annulated Oxygen and Sulfur Heterocycles by Tri-n-butyl Tinhydride–Mediated Aryl Radical Cyclization

The tin hydride–mediated cyclizations of a number of ethers, sulfides, and sulfones under mild, neutral conditions have been investigated. While the 2-bromobenzyloxy ethers were prepared in 62–65% yields by the alkylation of 4-hydroxy-1-phenyl-1,8-naphthyridin-2(1H)-one with 2-bromobenzyl bromides in refluxing acetone in the presence of anhydrous potassium carbonate, the sulfides were derived from 4-mercapto-1-phenyl-1,8-naphthyridin-2(1H)-one and 2-bromobenzyl bromides in 82–84% yields by a phase-transfer catalysis (PTC) reaction. The corresponding sulfones were prepared by treatment of the sulfides with m-CPBA in refluxing dichloromethane. The ethers, sulfides, and the sulfones were treated with ⁿ Bu₃SnH-AIBN to give regioselectively 1,8-naphthyridinone-annulated oxygen and sulfur heterocycles in 70–78% yields.