Β-unsaturated Sulfones Research Articles

Regulation of Photogenerated Redox Species through High Crystallinity Carbon Nitride for Improved C-S Coupling Reactions.

A novel and efficient approach for the synthesis of α, β-unsaturated sulfones through heterogeneous photocatalyzed C-S coupling reactions have been developed. The use of molten-salt method derived carbon nitride (MCN), a transition metal-free polymeric photocatalyst, combined with enhanced crystallinity and potassium iodide as an additive, effectively modulates photogenerated reactive redox species, markedly increasing the overall reaction selectivity. This method achieves the shortest reaction time (2 h) with high yield (up to 95 %) among the reported heterogeneous catalytic C-S bond formation reactions, matching the efficiency of the homogeneous photocatalysts. Furthermore, the application to challenging alkyne substrates has been demonstrated, underscoring the potential for a broad range of applications in pharmaceutical research and synthetic chemistry.

Stereoselective Synthesis of Z-α,β-Unsaturated Sulfones

Stereoselective Synthesis of Z-α,β-Unsaturated Sulfones

Stereoselective Synthesis of Z-α,β-Unsaturated Sulfones Using Peterson Reagents.

New Peterson reagents were prepared by introducing alkyloxy groups on the silicon atom in order to fix the conformation of the sulfone anion. The reagents 1d and 1e reacted with a variety of aldehydes after the treatment with Li-base to give Z-α,β-unsaturated sulfones with up to >99:1 selectivity in good to excellent yields. For the reaction with aliphatic aldehydes, CPME (cyclopentyl methyl ether) is the choice of solvent, while DME (1,2-dimethoxyethane) gave higher selectivity for the reaction with aromatic aldehydes.

ChemInform Abstract: Facile Synthesis of E-γ-Hydroxy α,β-Unsaturated Sulfones from Aldehydes.

Abstract Reaction of enolizable aldehydes with p-tolylsulfinylmethyl phenyl sulfone (1), in the presence of piperidine in acetonitrile at O°C, gave selectively E-γ-hydroxy-α,β-unsaturated phenyl sulfones in good yields.

ChemInform Abstract: Synthesis and Conjugate Additions to E-γ-Alkoxy-α- Substituted α,β-Unsaturated Sulfones.

Abstract (E)-γ-hydroxy-α,β-unsaturated sulfones have been readily functionalized at α-position via protection of hydroxyl group, metalation with n-BuLi and subsequent reaction with electrophiles. The conjugate addition of organolithiums to (E)-γ-methoxymethoxy-α-trimethylsilyl-α,β-unsaturated phenyl sulfones in Et 2 O is highly syn-stereoselective.

ChemInform Abstract: A New Method for the Dehydration of β-Hydroxy Sulfones. Synthesis of (E,S)-γ-Hydroxy-α,β-unsaturated Sulfones and (S)-. epsilon.-Hydroxy-(E,E)-α,γ-dienyl Sulfones.

ChemInform Abstract: A New Method for the Dehydration of β-Hydroxy Sulfones. Synthesis of (E,S)-γ-Hydroxy-α,β-unsaturated Sulfones and (S)-. epsilon.-Hydroxy-(E,E)-α,γ-dienyl Sulfones.

ChemInform Abstract: Flexible and Stereoselective Construction of Polypropionate Chains from Enantiomerically Pure γ-Hydroxy-α,β-unsaturated Sulfones.

Abstract Following an homologation sequence the readily available enantiomerically pure γ-hydroxy vinyl sulfone 2 has been transformed, with complete control of the stereochemistry, into γ-hydroxy vinyl sulfones of polypropionate structure. The four stereotriads have been prepared by stereoselective additions of organometallics to the vinyl sulfone moiety and by stereoselective reduction of β-hydroxyketones. In a similar way, these triads are the substrates for the stereoselective introduction of the fourth consecutive asymmetric center.

ChemInform Abstract: Stereoselective Synthesis of (-)-Swainsonine (XI) and 1,2-Di-epi-Swainsonine (IX) from γ-Hydroxy-α,β-unsaturated Sulfones.

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Remarkably Facile Hexatriene Electrocyclizations as a Route to Functionalized Cyclohexenones via Ring Expansion of Cyclobutenones.

AbstractFor Abstract see ChemInform Abstract in Full Text.

β-Ferrocenyl-α,β-unsaturated phosphonates and sulfones

Ferrocene reacts with β-ketophosphonates and β-ketosulfones (or acetals of formylphosphonates and sulfones) in the presence of a strong acid (triflic or methanesulfonic) to afford β-ferrocenyl-α,β-unsaturated phosphonates and β-ferrocenyl-α,β-unsaturated sulfones in good yield. The ( E)-stereochemistry of these compounds was confirmed by spectral and analytical data, as well as by X-ray diffraction.

Remarkably facile hexatriene electrocyclizations as a route to functionalized cyclohexenones via ring expansion of cyclobutenones.

This Communication describes a cascade reaction sequence that leads to highly functionalized cyclohexenones starting from reaction of cyclobutenones with alpha-lithio-alpha,beta-unsaturated sulfones and amides. The hexatriene-cyclohexadiene cyclization steps presumed to be involved in these transformations are among the most facile hexatriene electrocyclizations reported thus far.

Stereoselective Synthesis of (-)-Swainsonine and 1,2-di-epi-Swainsonine from γ-Hydroxy-α,β-unsaturated Sulfones

Stereoselective Synthesis of (-)-Swainsonine and 1,2-di-<i>epi</i>-Swainsonine from γ-Hydroxy-α,β-unsaturated Sulfones

Recent Applications of Vinyl Sulfones and Vinyl Sulfoxides in Asymmetric Synthesis

Herein we present some new synthetic applications based on the use of functionalized α,β-unsaturated sulfones and α,β-unsaturated sulfoxides. In particular, we have developed a stereodivergent approach to the synthesis of castanospermine stereoisomers from ω-amino-γ-oxygenated-α.β-unsaturated sulfones as well as a stereoselective synthesis of substituted dihydrofurans by Pd(0) catalyzed reaction of the carbonate derivatives of γ-oxygenated-α.β-unsaturated sulfones with methylene active ketones. Additionally, the use of the sulfinyl group as a novel chiral auxiliary in asymmetric Heck reactions is also described.

Recent Applications of Vinyl Sulfones and Vinyl Sulfoxides in Asymmetric Synthesis

Herein we present some new synthetic applications based on the use of functionalized α,β-unsaturated sulfones and α,β-unsaturated sulfoxides. In particular, we have developed a stereodivergent approach to the synthesis of castanospermine stereoisomers from ω-amino-γ-oxygenated-α.β-unsaturated sulfones as well as a stereoselective synthesis of substituted dihydrofurans by Pd(0) catalyzed reaction of the carbonate derivatives of γ-oxygenated-α.β-unsaturated sulfones with methylene active ketones. Additionally, the use of the sulfinyl group as a novel chiral auxiliary in asymmetric Heck reactions is also described.

Stereodivergent Synthesis of (-)- and (+)-Slaframine from γ-Hydroxy-α,β-unsaturated Sulfones

Stereodivergent Synthesis of (-)- and (+)-Slaframine from γ-Hydroxy-α,β-unsaturated Sulfones

One-Step Palladium-Catalyzed Synthesis of Substituted Dihydrofurans from the Carbonate Derivatives of γ-Hydroxy-α,β-unsaturated Sulfones

The palladium-catalyzed nucleophilic allylic substitution of the carbonate derivatives of γ-hydroxy-α,β-unsaturated sulfones (2) with soft carbon nucleophiles such as malonates, β-keto esters, 1,3-diketones, and α-sulfonyl ketones took place cleanly and with full regiocontrol (γ-substitution). Typical optimized conditions are Pd2(dba)3 (5 mol %), dppe (20 mol %), molecular sieves, in toluene−THF at 100 °C. Unexpectedly, when β-keto esters, 1,3-diketones, and α-sulfonyl ketones were used as nucleophiles a cascade process occurred, via initial γ-regioselective allylic substitution and further intramolecular conjugate addition of the enol moiety to the α,β-unsaturated sulfone, to give 2,3,4,5-tetrasubstituted dihydrofurans (13−25) in moderate to good yields. Moreover, the cyclization step is highly stereoselective giving predominantly or exclusively the 4,5-dihydrofuran of trans configuration. From readily available enantiopure (S)-2, this one-step procedure of synthesis of substituted dihydrofurans has been...

γ-Oxygenated-α,β-unsaturated sulfones in radical cyclizations and cascade processes

A wide variety of radical precursors having the structure of γ-oxygenated-α,β-unsaturated sulfone (substrates 1–4) have been prepared. Both 5-hexenyl and 6-heptenyl radicals, generated by reaction of substrates 1–4 with Bu 3SnH/AIBN, underwent an efficient cyclization via intramolecular addition to the vinyl sulfone moiety. By introduction of a double bond joined to the oxygen at γ-position, a cascade process based on two sequential radical cyclizations took place, affording highly substituted 2-oxa[3.3.0] or 9-oxa[4.3.0] bicyclic compounds.

A stereoselective approach to polyhydroxylated quinolizidine alkaloids

Both 1,2,9-trihydroxylated and 1,2,3,9-tetrahydroxylated quinolizidines have been stereoselectively prepared in few steps and high overall yields from the readily available γ-oxygenated-α,β-unsaturated sulfones 1 and 2.

Stereoselective formation of α-fluoro-α-trifluoromethyl-γ-lactones starting from γ-hydroxy-α,β-unsaturated sulfones and a hexafluoropropene-diethylamine adduct (PPDA)

( E)-3-Hydroxy-1-alkenyl p-tolyl sulfones ( 1) reacted with a hexafluoropropene-diethylamine adduct (PPDA) to afford α-fluoro-α-(trifluoromethyl)-β-[( p-tolylsulfonyl)methyl]-γ-lactones ( 2). This reaction is so stereoselective that only one diastereomer of 2 is detected in the reaction mixture. A plausible mechanism for this intriguing reaction is discussed.

Efficient Synthesis of Indolizidine Alkaloids from γ-Hydroxy-α,β-unsaturated Sulfones

An efficient and stereoselective synthesis of polyhydroxylated indolizidine alkaloids from readily available N-substituted γ-hydroxyvinyl sulfones is described.