Reactions Of Thioketones Research Articles

Synthesis of Heterocycles From Thio- and Selenocarbonyl Compounds

abstract Reactions of thioketones, sulfines, and thiosulfines were reviewed. Thioaldehydes and thioketones were formed by the reaction of phosphonium ylides with elemental sulfur. Prolonged heating of this reaction resulted in the formation of thiosulfine intermediates, which were treated with DMAD or thiones to give the corresponding adducts. Selenocarbonyl compounds were also formed by this method. α-Dithiolactone was synthesized by the reaction of di-tert-butylthioketene S-oxide with Lawesson's reagent. α-Disulfines were isolated by the reaction of thiocamphor derivatives with S2Cl2 followed by oxidation.

Reaction of thioketones with propiolic acids

The reaction of adamantane-2-thione with propiolic acid afforded a novel type of cycloadduct, spiro[adamantane-2,2'-6'H-[1,3]-oxathiin]-6'-one (3a), in quantitative yield. The reaction of thiobenzophenone with propiolic acid gave 2,2-diphenyl-6'H-[1,3]-oxathiin]-6'-one and 4-phenyl-3-thia-3,4-dihydronaphthoic acid in 34% and 35% yields, respectively. The reaction might proceed through a concerted process, as confirmed by kinetics. The reaction of adamantane-2-thione with 2-butynoic acid or phenylpropiolic acid gave the corresponding adducts regioselectively. Interestingly, only one isomer was obtained by the reaction of thiofenchone with propiolic acid, suggesting that the reaction proceeded diastereospecifically. Oxidation of adducts by dimethyldioxirane or m-chloroperoxybenzoic acid gave the corresponding sulfoxides and sulfones. The sulfoxides were thermally decomposed to give disulfide or another type of 1,3-oxathiin-6-one.

Reaction of Thioketones with (R)‐2‐Vinyloxirane: Regio‐ and Stereoselective Formation of (S)‐4‐Vinyl‐1,3‐oxathiolanes

AbstractThe reactions of 4,4'‐dimethoxythiobenzophenone (1), 9H‐xanthene‐9‐thione (2), and adamantane‐2‐thione (3) with (R)‐2‐vinyloxirane [(R)‐6] in the presence of SiO2 in anhydrous CH2Cl2 at 0 °C or room temperature afforded the corresponding 4‐vinyl‐1,3‐oxathiolane derivatives (S)‐7, (S)‐9, and (S)‐11, respectively. The analogous BF3‐catalyzed reactions of (R)‐6 with 1,1,3,3‐tetramethylindane‐2‐thione (4) and 2,2,4,4‐tetramethyl‐3‐thioxocyclobutanone (5) in anhydrous CH2Cl2 at –65 °C or –78 °C yielded the corresponding spirocyclic 1,3‐oxathiolanes (S)‐12 and (S)‐14, respectively. The structures of (S)‐9 and (S)‐12 were established by X‐ray crystallography. In all cases, the nucleophilic thiocarbonyl S atom attacked predominantly C(2) of the Lewis acid‐activated (R)‐2‐vinyloxirane ring with inversion of the configuration through an SN2‐type mechanism. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Studies on Reactions of Thioketones with Trimethyl(trifluoromethyl)silane Catalyzed by Fluoride Ions

Treatment of 2,2,4,4-tetramethylcyclobutane-1,3-dione (6) in THF with CF3SiMe3 in the presence of tetrabutylammonium fluoride (TBAF) yielded the corresponding 3-(trifluoromethyl)-3-[(trimethylsilyl)oxy]cyclobutanone 7 (Scheme 1) via nucleophilic addition of a CF anion at the CO group and subsequent silylation of the alcoholate. Under similar conditions, the ‘monothione' 1 reacted to give thietane derivative 8 (Scheme 2), whereas in the case of ‘dithione' 2 only the dispirodithietane 9, the dimer of 2, was formed (Scheme 3). A conceivable mechanism for the formation of 8 is the ring opening of the primarily formed CF3 adduct A followed by ring closure via the S-atom (Scheme 2). In the case of thiobenzophenones 4, complex mixtures of products were obtained including diarylmethyl trifluoromethyl sulfide 10 and 1,1-diaryl-2,2-difluoroethene 11 (Scheme 4). Obviously, competing thiophilic and carbophilic addition of the CF anion took place. The reaction with 9H-fluorene-9-thione (5) yielded only 9,9′-bifluorenylidene (14; Scheme 6); this product was also formed when 5 was treated with TBAF alone. Treatment of 4a with TBAF in THF gave dibenzhydryl disulfide (15; Scheme 7), whereas, under similar conditions, 1 yielded the 3-oxopentanedithioate 17 (Scheme 9). The reaction of dithione 2 with TBAF led to the isomeric dithiolactone 16 (Scheme 8), and 3 was transformed into 1,2,4-trithiolane 18 (Scheme 10).

Reactions of Thioketones with Dichlorocarbene

The reactions of sterically crowded cycloalkanethiones of type 2 with CHCl3/NaOH under phase-transfer catalysis (PTC) with benzyl(triethyl)ammonium chloride (TEBA) as catalyst afforded the corresponding `gem.-dichlorothiiranes' of type 3 in good yields (cf. Scheme 2 and Table). The desulfurization, which, in some cases, occurred spontaneously, led to (dichloromethylidene)cycloalkanes of type 4. Similar results were obtained using Seyferth's reagent in boiling benzene. In the case of 2,2,6,6-tetramethylcyclohexanethione, reaction under PTC conditions after 3 h yielded only the corresponding dichloromethylidene derivative; on the other hand, workup after 1 h gave (2,2,6,6-tetramethylcyclohexylidene)methanethione (thioketene 9; Scheme 5).

Reactions of Thioketones with a Fluorinated ThioneS-Imide

N-(1-Adamantyl)hexafluorothioacetone S-imide (1) reacts readily with aromatic thioketones 4a−e to afford 1,4,2-dithiazolidines 5a−e as products of [3 + 2] dipolar cycloadditions. Unexpectedly, cycloadducts 5d and 5e, obtained from thioxanthione (4d) and 4,4′-(dimethoxy)thiobenzophenone (4e), respectively, are found to decompose at room temperature and could not be isolated as pure compounds. Unlike aromatic thiones, adamantanethione (4f) did not react with 1 at ambient temperature. However, reaction did occur upon heating in a sealed tube, and the new 1,4,2-dithiazolidine 9, bearing two adamantyl moieties, was isolated as the major product. The structure of 9 has been determined by X-ray diffraction analysis. The connectivity of the heterocyclic ring in this product indicates that the mechanism of its formation must proceed by a different route involving another in situ generated sulfur-centered 1,3-dipole. Retrocycloaddition of the primary adamantanethione cycloadduct 13 liberates hexafluorothioacetone, which is subsequently captured by S-imide 1 to give tetrakis(trifluoromethyl)-1,4,2-dithiazolidine 8 as a crystalline product. The structure of 8 has also been confirmed by X-ray diffraction analysis.

ChemInform Abstract: Reactions of Thioketones with Methyl Azidoacetate.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Reaction of thioketones with carbonyl oxides and 3,3-dimethyl-1,2-dioxirane. [3 + 2] Cycloaddition vs. oxygen atom transfer

The ozonolysis of vinyl ethers 1a, b in the presence of adamantane-2-thione 4a and bicyclo[3.3.1]nonan-9-thione 4b gave in each case the corresponding thioozonides 5a–c in moderate yields, whilst ozonolysis of a mixture of vinyl ethers 1a–d and thiobenzophenone derivatives 4f–h gave the corresponding thione S-oxides 8f–h in isolated yields of 10–40%, together with the benzophenones 7f–h. 3,3-Dimethyl-1,2-dioxirane, generated in situ from the reáction of acetone and ‘oxone’(2KHSO5- KHSO4-K2SO4), transferred an oxygen atom to compounds 4a, f, g, i providing the thione S-oxides 8a, f, g, i in 29–97% yield.

Mehrstufige Redoxsysteme. XLIX. Mitteilung. Mit π‐Systemen substituierte 1,3‐Dimethylidencyclobutane: Synthese und Eigenschaften

Multistep Redox Systems. 1,3‐Dimethylidenecyclobutanes Substituted by π‐Syntheses and PropertiesAs potential redox systems 1,3‐dimethylidenecyclobutanes are synthesized in which the ‘exo’‐methylidene group participates in a cyclopentadienyl (typeC4)or cycloheptatrienyl (type A5) system. Benzo‐annellated systems are also described. The formation of the CC bond by the reaction of thioketones (3 and 31) with diazo compounds is extended to extended to 1,6,7,21, and 24, which so far had not been employed. In some cases, intermediate thiiranes can be isolated (e.g.4) which are smoothly transformed into the target compounds of types C4 and A5 by extrusion of sulfur. The new CC bonds may be introduced stepwise, thereby allowing the synthesis of unsymmetrically substituted 1,3‐dimethylidenecyclobutanes (e.g. 20 and 35). Reduction of by Na does not produce bicyclobutanes but compounds 43 and 44 with one dihydrofulvene unit.

New Methods and Reagents in Organic Synthesis. 68. Reaction of Thioketones with Lithium Trimethylsilyldiazomethane

La reaction du titre donne des alcynes vinylsilanes, thiadiazole-1,2,3ines ou thiadiazoles-1,2,3 selon les substrats et les solvants

Strain-assisted .alpha.-cleavage reactions of thioketones: cyclobutanethiones

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStrain-assisted .alpha.-cleavage reactions of thioketones: cyclobutanethionesK. Muthuramu, B. Sundari, and V. RamamurthyCite this: J. Org. Chem. 1983, 48, 24, 4482–4487Publication Date (Print):December 1, 1983Publication History Published online1 May 2002Published inissue 1 December 1983https://doi.org/10.1021/jo00172a008RIGHTS & PERMISSIONSArticle Views218Altmetric-Citations15LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (689 KB) Get e-Alerts Get e-Alerts

Strain assisted .alpha.-cleavage reactions of thio ketones: diphenylcyclopropenethione

Strain assisted .alpha.-cleavage reactions of thio ketones: diphenylcyclopropenethione

Dichotomous reactions of thioketones with tetracarbonylferrate

Treatment of nonenolizable and enolizable thioketones, first with disodium tetracarbonylferrate and then with an acid chloride, affords saturated and unsaturated thioesters, respectively. Mechanisms are proposed for these different reactions.

Angular versus linear transition state in nucleophilic reactions of thioketones

The steric effect of o-methyl groups is much more pronounced for N-alkylation with Mel, Etl, and PriI or aza-aromatic compounds than for S-alkylation of heterocyclic thiones. This is explained by comparison of van der Waals interactions in the transition states of chosen homomorphic systems; an angular transition state is shown to conform with the measured kinetic constants.

Reactions of thioketones. Part III. Reaction of chloramine T with aliphatic and aromatic thioketones

Chloramine T reacted readily with aliphatic and aromatic thiones, acting as a nucleophilic and as an oxidizing reagent. The non-thioenolizable thiones, thioadamantanone and thiobenzophenone afforded thio-ozonide products. Thiocamphor, however, gave an unsaturated disulphide dimer which on heating underwent a stereospecific Cope-type rearrangement.

Reactions of thioketones. Part II. Thio-ozonide formation in some nucleophilic reactions of thioketones with amines and with benzenethiol

Thiobenzophenone (5) and thioadamantanone (15) have been shown to react with certain amines under ambient conditions to give low yields of the thio-ozonides 3,3,5,5-tetraphenyl-1,2,4-trithiolan (1) and dispiro[adamantane-2,3′-(1,2,4-trithiolan)-5′,2″-adamantane](16) respectively. Reaction of (5) with benzenethiol also gave the thio-ozonide (1), whereas (15) gave 2,2′-bi-2-phenylthioadamantyl disulphide (21). Aminosulphuric acid reacted with (5) in the presence of base to give benzophenone oxime and (1). Parallel reactions with aliphatic thiones gave mainly the oximes. Mechanisms are proposed to account for the formation of the thio-ozonides. Initial nucleophilic attack on the thione affords a tetrahedral intermediate which is oxidatively dimerized to an unstable disulphide. Possible intermediates leading to the thio-ozonides are suggested.