Cross-metathesis reaction of vinyl sulfones and sulfoxides

Cross-metathesis reactions of α,β-unsaturated sulfones and sulfoxides in the presence of molybdenum and ruthenium pre-catalysts were tested. A selective metahesis reaction was achieved between functionalized terminal olefins and vinyl sulfones by using the ‘second generation’ ruthenium catalysts 1c-h while the highly active Schrock catalyst 1b was found to be functional group incompatible with vinyl sulfones. The cross-metathesis products were isolated in good yields with an excellent (E)-selectivity. Both the molybdenum and ruthenium-based complexes were, however, incompatible with α,β- and β,γ-unsaturated sulfoxides.     

The mass spectra of styryl sulfoxides and sulfones

A variety of rearrangement reactions have been documented in the gas phase ion chemistry of styryl sulfoxides and sulfones. The styryl group rearranges from sulfur to oxygen as evidenced by loss of SCH₃ from methyl styryl sulfoxide and loss of SOCH₃ from the corresponding sulfone. The resulting m/e 119 ion loses carbon monoxide in one fragmentation route and alternatively loses a hydrogen atom from the aromatic nucleus to produce the benzofuran molecule ion via an electrophilic aromatic ring closure reaction. Styryl sulfoxides lose both carbon monoxide and formyl radicals directly from their molecule ions, but the corresponding sulfones do not fragment in this manner. The mechanisms of the above reactions, as well as others, were investigated using substituent and deuterium labeling. The styryl group has been shown to migrate in preference to a phenyl or substituted phenyl group by investigation of the mass spectra of appropriate aryl styryl sulfoxides and sulfones.     

Synthesis of fluorinated allylic amines: Reaction of 2-(trimethylsilyl)ethyl sulfones and sulfoxides with fluorinated imines

A new synthesis of fluorinated allylamines through the reaction of 2-(trimethylsilyl)ethyl sulfones and sulfoxides (as vinyl anion equivalents) with imines and imino esters has been described. The process includes a TBAF-mediated fragmentation of 2-(trimethylsilyl)ethyl sulfones to afford the desired allylic amines. When the reaction is performed with the corresponding sulfoxides, the fragmentation takes place under the addition conditions, affording the final products in a single step.     

New synthesis of allylidenecyclobutanes by the reaction of cyclobutylmagnesium carbenoids with vinyl sulfones

The reaction of cyclobutylmagnesium carbenoids, which were generated from 1-chlorocyclobutyl p-tolyl sulfoxides with EtMgCl via the sulfoxide-magnesium exchange reaction at low temperature, with carbanions derived from vinyl sulfones with n-BuLi or LDA resulted in the formation of allylidenecyclobutanes in moderate to good yields. The actual reactive species of the sulfones in this reaction were proved to be the lithium α-sulfonyl carbanion of allyl sulfones derived from the vinyl sulfones by double bond migration with the bases used. Mono- and di-substituted allylidenecyclobutanes can be obtained by using a variety of vinyl sulfones.     

Oxidative addition of Pd0 to Ar-SO2R bonds: heck-type reactions of sulfones

[reaction: see text] Phenyl vinyl sulfones and sulfoxides react with Pd(OAc)(2) to form styryl sulfoxides and sulfones according to the first Mizoroki-Heck reaction reported for these thio derivatives. Only sulfones are able to react by using catalytic amounts of Pd (up to 1 mol %) in the presence of Ag(2)CO(3). 1,2-Diphenylsulfonyl ethenes, alkynylphenyl sulfones, and other sulfones, less prone to act as acceptors in the Heck-type reactions, can transfer the aryl group to alkyl acrylates forming cinnamic esters.     

From vinyl sulfides, sulfoxides and sulfones to vinyl zirconocene derivatives

An easy and straightforward new method for the preparation of sp² zirconocene derivatives from a wide range of heterosubstituted alkenes such as vinyl sulfides, sulfoxides and sulfones is described. In all cases, a complete isomerization of the stereochemistry is observed and only the E-isomer is obtained. The reactivity of the resulting vinylic organometallic can be increased by a transmetalation reaction into organocopper, organozinc or organopalladium species and, therefore, several carbon-carbon formation were easily realized.     

Pd-catalyzed sulfinylzincation of activated alkynes with 1-alkynyl sulfoxides as a sulfinyl source

Unprecedented Pd-catalyzed sulfinylzincation with 1-alkynyl sulfoxide as a sulfinyl source was developed. Bis-sulfinyl alkenes were formed in good yields on treatment of 1-alkynyl sulfoxides with Et(2)Zn in the presence of a Pd-catalyst, wherein zinc sulfenate (or sulfinylzinc) species would be generated in situ to undergo highly syn-selective conjugate addition to the 1-alkynyl sulfoxides. By using 3,3-dimethyl-1-butynyl sulfoxides, formation of the bis-sulfinyl alkenes was completely suppressed and the sulfinylzincation of activated alkynes was accomplished. The reaction tolerates various functionalities, and was promoted considerably by the neighboring group participation of the heteroatom at the delta-position in the alkynoates. Stereodivergent synthesis of two diastereomeric vinylic sulfoxides and reaction of the resulting vinylzinc species with electrophiles were also described.     

1，2－联烯亚砚和1，2－联烯砜的反应

1，2－联烯亚砜和1，2－联烯砜是重要的含硫联烯化合物，综述了1，2－联烯 亚砜和1，2－联烯砜的亲核加成、亲电加成、Diels-Alder反应、1，3－偶极加成 、[2+2]环加成等反应以及在天然产物中的应用。     

Diastereoselective radical hydrogenation of alpha-(1-Hydroxyalkyl)vinyl sulfoxides and sulfones controlled by intramolecular hydrogen bonding

The reaction of (S)-alpha-(1-hydroxyalkyl)vinyl sulfoxides (S)-5 with alkyl radicals and tributyltin hydride gave the addition-hydrogenation products with high diastereoselectivity, whereas the reaction with (R)-alpha-(1-hydroxyalkyl)vinyl sulfoxides (R)-5 resulted in complete recovery of the starting sulfoxides. Stereoselective intramolecular hydrogen bonding between the hydroxy group and the diastereotopic sulfonyl oxygen led to high diastereoselectivity in the radical reaction of alpha-(1-hydroxyethyl)vinyl sulfone 12. An important role of intramolecular hydrogen bonding on the diastereoselectivity as well as the reactivity toward alkyl radicals is discussed.     

Oxidation of aromatic sulfides with molecular oxygen: Controllable synthesis of sulfoxides or sulfones

The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted. The sulfoxides and sulfones could be obtained by simply switching the reaction media, i.e., bis(2-butoxyethyl)ether (BBE) or poly(ethylene glycol)dimethyl ether (PEGDME). The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents. This strategy represents an economic and eco-friendly method that could find potential applications.     

Oxidation of aromatic sulfides with molecular oxygen: Controllable synthesis of sulfoxides or sulfones

The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted. The sulfoxides and sulfones could be obtained by simply switching the reaction media, i.e., bis(2-butoxyethyl)ether (BBE) or poly(ethylene glycol)dimethyl ether (PEGDME). The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents. This strategy represents an economic and eco-friendly method that could find potential applications.     

Carbon-oxygen bond formation in electron-impact ions of acetylenic sulfoxides and sulfones

Migration of the ethynyl group, from sulfur to oxygen in acetylenic sulfoxides and sulfones leads to several documented examples of carbon-oxygen bond forming rearrangement reactions.     

NMR-spectroscopic study of conjugation effects. 9.13C NMR spectra of alkyl vinyl sulfoxides and sulfones

Conclusions Polarization and steric effects of the alkylhetero groups have the main influence on the C^1,2 chemical shifts of the vinyl fragment in alkyl vinyl sulfoxides and sulfones. In sulfones, an appreciable role can be played by a -acceptor interaction between the sulfur atom and the double bond.For the previous communication, see [I].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1007–1011, May, 1980.     

Geometrically selective synthesis of functionalized beta,beta-disubstituted vinylic sulfoxides by Cu-catalyzed conjugate addition of organozinc reagents to 1-alkynyl sulfoxides

[reaction: see text] A new synthetic method of chiral beta,beta-disubstituted vinylic sulfoxides bearing various functionalities has been developed by employing Cu-catalyzed conjugate addition of an organozinc reagent to chiral 1-alkynyl sulfoxide. Since the reaction proceeds with very high syn-selectivity, both geometric beta,beta-disubstituted vinylic sulfoxides were stereoselectively synthesized by changing the combination of 1-alkynyl sulfoxide and the organozinc reagent.     

A new entry to oxacycles via base-catalyzed endo mode cyclization of allenyl sulfoxides and sulfones

[reaction: see text]. Treatment of the allenyl sulfoxides and sulfones possessing a proper delta-hydroxy appendage at the C-1 position with potassium tert-butoxide effected endo mode ring closure at the sp-hybridized carbon center of the allenyl moiety to provide the five- to eight-membered oxacycles in high yields.     

Perfluoroalkylation of 2-mercaptoethanol as a key step for a new synthesis of perfluoroalkyl vinyl sulfides, sulfoxides and sulfones

We have developed a new method of perfluoroalkylation of thiols, using a mixture of sodium formate/sodium sulfite to generate a sulfoxylate radical anion. This method is compatible with alcoholic functionality and was applied to mercaptoethanol. The obtained compounds were transformed into perfluoroalkyl vinyl sulfides, sulfoxides and sulfones.     

A one-carbon ring enlarged cyclopropanation or vinylation reaction of cyclic keto eaters or sulfones

On treating potassium salts of n-membered cyclic keto esters or sulfones with phenyl 1-propenyl selenone, a one-carbon ring expansion reaction involving cyclopropanation or vinylation takes place to give the corresponding bicyclo[(n - 1).1.0]alkanones or (n + 1)-membered cyclic ketones bearing vinyl group at their 3-position.     

1,1,2,2-Tetrahydroperoxy-1,2-diphenylethane as new oxidant for chemoselective and catalyst free oxidation of sulfides to sulfoxides and sulfones

A catalyst free and chemoselective oxidation of sulfides to sulfoxides or sulfones was developed using 1,1,2,2-tetrahydroperoxy-1,2-diphenylethane as a new oxidant. This scope has shown the achievement of various sulfoxides and sulfones which were obtained selectively in high yields at room temperature.     

Controllable oxidation of sulfides to sulfoxides and sulfones with aqueous hydrogen peroxide in the presence of β-cyclodextrin

A facile procedure has been developed for the transition metal-free oxidation of sulfides to sulfoxides and sulfones and of sulfoxides to sulfones with hydrogen peroxide in aqueous medium in the presence of β-cyclodextrin as catalyst. The procedure allows formation of sulfoxide or sulfone to be controlled. Published in Russian in Zhurnal Organicheskoi Khimii, 2006, Vol. 42, No. 7, pp. 979–981. The original text was submitted by the authors in English.     

Highly stereoselective synthesis of functionalized beta,beta-di- and trisubstituted vinylic sulfoxides by Cu-catalyzed conjugate addition of organozinc reagents

beta,beta-Disubstituted chiral vinylic sulfoxides bearing functionalities have been synthesized via Cu-catalyzed conjugate addition of organozinc reagents to chiral 1-alkynyl sulfoxides. Due to the availability of functionalized organozinc reagents and high syn-selectivity of the reaction, both geometric beta,beta-disubstituted vinylic sulfoxides were selectively synthesized. Furthermore, 1-alkynyl sulfoxides were derivatized into trisubstituted vinylic sulfoxides by trapping the resulting alpha-sulfinyl vinylic carbanion with electrophiles. Highly diastereoselective THF and THP ring formations were accomplished by means of this methodology followed by an intramolecular Michael addition.