Carbon-carbon bond-forming reaction of cyclic sulfonium ylides stabilized by a carbonyl group

Rhodium(II)-catalyzed decomposition of diazoketones 1 and 5 bearing a cyclic dithioacetal, in the presence of aldehyde and ClTi(Oi-Pr)(3), afforded both or one of the C=C-bonded products, i.e., ring-enlarged enone 2 and ring-transformed thiophenone 3, that were formed between aldehyde and intermediate bicyclosulfonium ylide. The stereochemistry of the exocyclic C=C bond in the products was exclusively Z. The sulfonium atom that transiently composed the ylide was incorporated into products, but no oxirane was formed.     

Spectra and structure of sulfonium C-mononitro ylides

Conclusions Based on the data of the vibrational spectra and quantum-chemical calculation, in its electronic structure the nitro group in sulfonium C-nitro ylides is closer to the nitro groups in nonionized nitro compounds than in their salts.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1403–1406, June, 1981.     

Spectra and structure of sulfonium C-dinitro ylides

Conclusions Based on the data of the vibrational spectra of sulfonium C-dinitro ylides and the quantum-chemical calculation of the electronic structure of the molecule the nitro groups of dinitro ylides in their electronic structure differ substantially from the nitro groups of both the gem-dinitroalkanes and their salts.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1407–1409, June, 1981.     

Sulfur ylides. 5. Reactions of phthalimide-containing keto-stabilized sulfonium ylides

Some reactions of phthalimide-containing keto-stabilized sulfur ylides have been investigated. It was established that in addition to the formation of the usual products for keto-stabilized sulfur ylides, the reaction with acrylonitrile is accompanied by a rearrangement and leads to 1,1-disubstituted cyclopropanes.Institute of Chemistry, Bashkir Science Center, Urals Branch, Russian Academy of Sciences, 450054 Ufa. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 720–726, March, 1992.     

Carbon-13 NMR spectroscopy of sulfonium ylides

C-13 NMR data for a series of stabilized and unstabilized ylides indicate flattening at the ylidic carbon with respect to the parent salts. For unstabilized ylides association between the carbanionic center and the lithium cation cannot be neglected.     

硫叶立德途径立体控制合成乙烯基型环氧化合物

在相转移条件下(CH3CN/KOH/RT)乙烯基型硫叶立德和醛反应高产率地得到以反式为主的产物,而在低温溴化锂存在下(LiBr/KHMDS/THF/-90℃)得到以顺式为主的产物,对于通过反应条件的变换而改变反应产物立体化学的机理,给出了一个初步的解释。     

Stereochemistry of methylation of cyclic sulfonium ylides

Low temperature methylation of 6-membered sulfonium ylides is highly stereoselective and configurational inversion has been established in at least one case. No appreciable stereoselectivity has been observed in 5-membered ylides.     

Reaction of sulfonium ylides complexed with tricarbonylchromium

Oxiranes and olefins are obtained from the reactions of free and complexed phenylmethylsulfonium methylides with tricarbonylchromium with benzophenone, benzaldehyde and cyclohexanone. Good yields of olefins are obtained from the Cr(CO)₃ complexes with benzophenone, but yields of 0.1-0.5% are obtained with benzaldehyde and cyclohexanone.     

Synthesis of some sulfonium salts and ylides containing the isoxazole nucleus

Some dimethylisoxazolylmethylsulfonium salts and the corresponding ylides were synthetized and their chemical behaviour studied. Dimethylsullonium-5-isoxazolyl methylides (XIa,b) give 5-isoxazolyloxiranes (XIIa,d) and XIII when allowed to react with carbonyl compounds. Ring opening products from these oxiranes are also reported.     

Synthesis and applications of chiral organoboranes generated from sulfonium ylides

The reactions of aryl-stabilized sulfonium ylides with trialkyl/triarylboranes have been investigated. Clean monohomologation of the boranes with only a small amount of the higher homologation products (<10%) was observed. The homologation products were isolated as the alcohols (treatment with H2O2/NaOH) and amines (treatment with NH2OSO3H). Although the reactions were conveniently conducted at 5 degrees C, the ylide reaction with tributylborane was very fast even at -78 degrees C (complete after 15 min). Use of chiral sulfides rendered the reactions asymmetric, and high enantioselectivity (>95% ee) was observed in all cases. The ylide-borane reaction was applied to short syntheses of the anti-inflammatory agents neobenodine and cetirizine, both of which contain a chiral diarylmethylalkoxy and diarylmethylamino moiety, respectively.     

An efficient synthesis of isothiazolidines via sulfonium ylides formed by the reaction of thietanes and nitrene

An efficient synthesis of isothiazolidines in good yields is described.     

Use of sulfonium ylides in the synthesis of heterocyclic systems (review)

The literature on the use of sulfur ylides in the synthesis of heterocyclic systems of varied structure is reviewed. The possible preparative value of these reactions is discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 147–173, February, 1990.     

Reactions of distabilized β-dicarbonyl sulfonium and iodonium ylides with isocyanates

The reactions of tosyl isocyanate with diethyl diphenylsulfuranylidenemalonate, 2-dimethylsulfuranylidenedimedone, and 2-dimethylsulfuranylideneindane-1,3-dione afforded 1,3-ditosyl-5,5-diethoxycarbonylimidazolidine-2,4-dione and tosylimination products at the keto groups, respectively. Phenyliodonium ylides derived from diethyl malonate and ethyl acetate react with 3,4-dichlorophenyl isocyanate to form substituted oxazolin-2-ones. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 854–861, May, 2006.     

Structure of pyrrolisidinediones — Products of the intramolecular cyclization of aminoketo-stabilized sulfonium ylides

The structure of three pyrrolisidinediones was determined by x-ray crystallographic analysis. A pseudocentrosymmetrical structure of the dimer crystal with a molecule of water of crystallization close to the inversion center was detected in the oxidation product.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1797–1802, August, 1991.