The stereochemistry of oxidation at sulfur

Johnson, Carl R.; Diefenbach, H.; Keiser, Jeffrey E.; Sharp, Joanne

doi:10.1016/s0040-4020(01)83071-4

Cited by 28 publications

(4 citation statements)

References 5 publications

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“…Table 2),18 which has been attributed to a highly efficient σ S–C → σ* S–O stereoelectronic interaction (Figure 2, top), possible only when the bonds involved adopt an antiperiplanar orientation. In contrast, oxygenated thianes show a different stability pattern;24 the axial thiane 1‐oxide is more stable than the equatorial substrate (Δ E = 1.3 kJ/mol18), most probably due to a somewhat less effective σ H–C → σ* S–O interaction (Figure 2, bottom).…”

Section: Resultsmentioning

confidence: 99%

Conformationally Constrained Oxides of 1,3‐Dithiane: Synthesis and NMR Spectroscopic Investigations

et al. 2012

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Conformationally constrained derivatives of 1,3‐dithianes (5‐tert‐butyl‐ and 4,6‐dimethyl‐1,3‐dithiane and dithiadecalin) have been oxidised with various oxidants to yield axial and equatorial sulfoxides, disulfoxides and sulfones. Axial sulfoxides were prepared by nucleophilic hydroxide addition to the corresponding 2‐alkylidene derivatives with subsequent retro‐aldol‐type elimination. The reaction outcome is related to the relative energies of the derivatives, as demontstrated by DFT calculations. The NMR spectroscopic data of the compounds obtained were analysed to identify 4J couplings. It was found that only 4J W couplings can be observed regardless of whether there is an axial or an equatorial sulfoxide, sulfide or sulfone group present in between the respective C–H moieties. A previously postulated γ‐gauche effect of axial sulfoxides (but not of equatorial sulfoxides or sulfones) leading to the shielding of carbon atoms is not unambiguously supported by the NMR spectroscopic data of conformationally fixed derivatives.

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Section: Resultsmentioning

confidence: 99%

Conformationally Constrained Oxides of 1,3‐Dithiane: Synthesis and NMR Spectroscopic Investigations

et al. 2012

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“…Oxidation of indole 9 with 1 or 2 equiv of m- CPBA gave the corresponding sulfoxide ( 10 , 72%, 2:3 inseparable mixture of diastereomers) or sulfone ( 11 , 99%). Treatment of these compounds with Gen 2 (10 mol % for the sulfoxide and 5 mol % for the sulfone) produced the corresponding thiazocinyl acetamide derivatives 12 and 16 in 48% and 89%, respectively (Scheme ).…”

Section: Resultsmentioning

confidence: 99%

Simple Thiazocine-2-acetic Acid Derivatives via Ring-Closing Metathesis

Bates

Jog

2004

J. Org. Chem.

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A new protocol for synthesis of 2-heterocylylacetic acid derivatives involving conjugate addition of allyl mercaptan to an acrylate containing a tethered olefinic site followed by RCM (ring-closing metathesis) is described. In this series, sulfanyl derivatives were unreactive, while sulfoxide and sulfone analogues provided the corresponding thiazocines in fair to excellent yields. Use of the sulfoxide oxidation state as a protecting group for sulfides inert to RCM is demonstrated also. Thus, oxidation of sulfide 9 [N-allyl-N-[2-(allylthio)-4-(1H-indol-1-yl)-4-oxobutyl]-4-methylbenzenesulfonamide] followed by cyclization yielded the corresponding thiazocine sulfoxide 12. Deprotection (deoxygenation) of 12 was accomplished using Lawesson's reagent, producing 1-[[4-[4-(methylphenyl)sulfonyl]-3,4,5,8-tetrahydro-2H-1,4-thiazocin-2-yl]acetyl]-1H-indole (21) in 67% unoptimized yield.

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“…Registry No. 1,2,3,4,5,7,6,[7][8][7][8]9, 95123-99-2; 10, 95124-00-8; 11, 95124-01-9; 12, 95124-02-0; 13, 95124-03-1; 14, 95124-04-2; 15, 95124-05-3; (MeO)2CH(CH2)9CH(OAc)CH=CH2, 88399-89-7; (£)-CH3CH=CHCH(OAc)CH3, 31001-80-6; CH=CCH2CH(C02C- Received September 10,1984 Diels-Alder adducts of cyclopentadiene and thiocarbonyl compounds2 are attractive intermediates for the controlled synthesis of polyfunctional cyclopentanoids through sulfur-mediated transformations followed by desulfurization. We find that erafosulfoxides 2, prepared stereospecifically from cyclopentadiene and alkanethial 5-oxides 1, readily rearrange to bicyclic sultenes 3, representatives of a rare class of sulfur heterocycles, which in turn may be easily converted to various cyclopentenoids including (£)-5-alkylidene-2-cyclopentenones (6) (eq 1).…”

Section: E• 15mentioning

confidence: 99%

“…The starting enynes5 are readily prepared by using the palladium(0)-catalyzed coupling of allylic carboxylates with dimethyl propargylmalonate anion [3][4][5]4Pd, NaH, THF, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] h at reflux]. As seen in Table I the yields are consistantly good (55-90%) with high chemo-, regio-, and stereoselectivity associated with the alkylation process.…”

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confidence: 99%