Stereochemistry of 1,3-dithia-5,6-benzocycloheptene-s-oxides

Klimovitskii, E. N.; Kikilo, P. A.; Dobrynin, A. B.; Kataeva, О. N.; Литвинов, И. А.; Fedorenko, V. Yu.; Shtyrlin, Yu. G.

doi:10.1016/j.molstruc.2003.10.009

Cited by 3 publications

(6 citation statements)

References 16 publications

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“…Firstly we assigned the multiplets at the allyl atoms C 4 and C 7 by comparing with the parameters in 13 C NMR spectra of six-and seven-membered cyclic sulfoxides [4,5] in combination with the 2D heteronuclear correlation STEREOCHEMISTRY OF SEVEN-MEMBERED HETEROCYCLES: XLVII. 13 C( 1 H) NMR spectroscopy.…”

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confidence: 99%

“…It was shown formerly that for monosulfoxides IV an equilibrium between forms chair and boat was characteristic [5,10,13] like in the case of the corresponding sevenmembered benzodithioacetals [14].…”

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“…For isomeric 2-tert-butyl derivatived IIc same as in the 2-alkyl(aryl)-substituted benzoanalogs IV [5,13]. The sterically strained chair conformations with the axial position of the bulky substituent were a priori excluded from the consideration, and the twist conformations proved to be unfavorable by energy.…”

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Stereochemistry of seven-membered heterocycles: XLVII. Synthesis, NMR, XRD, and theoretical investigation of monosulfoxides of (Z)-4,7-dihydro-1λ4,3-dithiepine series

et al. 2010

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By oxidation of (Z)-4,7-dihydro-1,3-dithiepines with meta-chloroperbenzoic acid the corresponding 4,7-dihydro-1λ 4 ,3-dithiepine 1-oxides were synthesized in ~85% yield. A complete assignment of signals in the 1 H and 13 C NMR spectra of the compounds obtained was established. According to XRD analysis the sevenmembered heterocycles crystallized in conformations chair or boat. The calculations by DFT method in the B3LYP/6-31G(d,p) version showed the possibility of conformational equilibrium of these forms in the gas phase. 6 5 7 4 O 1 3 2 S S R 1 R 2 S S R 1 R 2 O O III IV *For Communication XLVI, see [1].The information on reactions involving sevenmembered cyclic (Z)-4,7-dihydro-1,3-dithiepines are very scanty: These are reactions of proton transfer in homolytic processes [2] and of 1,3-dipolar cycloaddition [3]. No products of oxidation at the sulfur atom were described. Here we report on the synthesis of monosulfoxides IIa-IIc obtained by the oxidation with the meta-chloroperbenzoic acid of three dithioacetals: Ia has no substituents at the C 2 atom, Ib is a dithioketal, and Ic is a 2-monosubstituted compound. The oxidation occurred under mild conditions and afforded the target products in ~85% yield. The monosubstituted substrate Ic provided on oxidation a mixture of isomers trans-(IIc) and cis-(IIc) in a ratio 7:1. Analysis was performed of one-and two-dimensional 1 H and 13 C NMR spectra including the calculations of 1 H NMR spectra. The compounds obtained were also subjected to XRD and quantum-chemical investigations.The presence of a stereogenic heteroatomic center results in the nonequivalence of the endocyclic carbon atoms, including methyl groups of compound IIb, in the 1 H and 13 C NMR spectra. The geminal hydrogen atoms of methylene and methyl groups are diastereotopic, nonequivalent are also the vicinal hydrogen atoms at the double bond.Firstly we assigned the multiplets at the allyl atoms C 4 and C 7 by comparing with the parameters in 13 C NMR spectra of six-and seven-membered cyclic sulfoxides [4,5] in combination with the 2D heteronuclear correlation Scheme 2.

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Stereochemistry of seven-membered heterocycles: XLVII. Synthesis, NMR, XRD, and theoretical investigation of monosulfoxides of (Z)-4,7-dihydro-1λ4,3-dithiepine series

et al. 2010

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“…We previously showed that seven-membered cyclic dithio acetals with a planar fragment, 2-substituted 1,3-dithia-5,6-benzocycloheptenes I, are oxidized with m-chloroperoxybenzoic acid to the corresponding monosulfoxides II with high stereoselectivity [1,2]. According to the data of dynamic 1 H and 13 C NMR spectroscopy, sulfoxides II exist as equilibrium mixtures of chair (C) and boat (B) conformers with equatorial orientations of the substituents in the sevenmembered ring.…”

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“…Raising the temperature to 140°C (DMSO-d 6 ) leads to a spectral pattern corresponding to fast exchange (on the NMR time scale). 13 C NMR spectroscopy turned out to be very informative from the viewpoint of revealing conformational composition of nonrigid seven-membered heterocycles I and II [1,2,5,6] which exist in solution as equilibrium mixtures of chair and boat conformers. Their spectra are characterized by relatively upfield positions of signals from both benzylic and dithioacetal carbon atoms in the boat conformer.…”

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Synthesis and Stereochemistry of 1H,5H-Naphtho[1,8-ef][1,3]dithiocine 2-Oxides

et al. 2005

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3-Substituted 1H,5H-naphtho [1,8-ef][1,3]dithiocines (R = H, Me, Ph, t-Bu) were oxidized with m-chloroperoxybenzoic acid to the corresponding 2-oxides having trans configuration (R ≠ H). According to the 1 H and 13 C NMR data (including NOESY experiments), the disubstituted compounds at room temperature exist in a boat conformation with equatorial orientation of the substituent on C 3 and oxygen atom on S 2 . The compound with no substituent on C 3 gives rise to a mixture of boat conformers with axial and equatorial sulfoxide oxygen atoms at a ratio of 83 : 17.

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1,3-Dioxepanes, 1,3-Oxathiepanes, and 1,3-Dithiepanes

Frauenrath

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2008

Comprehensive Heterocyclic Chemistry III

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Stereochemistry of 1,3-dithia-5,6-benzocycloheptene-s-oxides

Cited by 3 publications

References 16 publications

Stereochemistry of seven-membered heterocycles: XLVII. Synthesis, NMR, XRD, and theoretical investigation of monosulfoxides of (Z)-4,7-dihydro-1λ4,3-dithiepine series

Stereochemistry of seven-membered heterocycles: XLVII. Synthesis, NMR, XRD, and theoretical investigation of monosulfoxides of (Z)-4,7-dihydro-1λ4,3-dithiepine series

Synthesis and Stereochemistry of 1H,5H-Naphtho[1,8-ef][1,3]dithiocine 2-Oxides

1,3-Dioxepanes, 1,3-Oxathiepanes, and 1,3-Dithiepanes

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