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Heimgartner Heinz - One of the best experts on this subject based on the ideXlab platform.
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Reactions of thiocarbonyl compounds with electrophilic and nucleophilic carbenes as well as with their metal complexes
'Informa UK Limited', 2020Co-Authors: Mlostoń Grzegorz, Heimgartner HeinzAbstract:A variety of cyclic and acyclic products are reported for reactions of thiocarbonyl compounds with carbenes and their metal complexed derivatives. Electrophilic and nucleophilic carbenes react with non-enolizable thioketones yielding thiocarbonyl ylides or 1,3-zwitterions, respectively, as plausible, reactive intermediates. In most cases, the initially formed intermediates undergo 1,3- electrocyclization yielding respective Thiiranes, which, depending on the substitution pattern, are either isolated as final products or extrude elemental sulfur forming substituted ethylene derivatives. In addition, reactive thiocarbonyl ylides formed from α-oxo substituted carbenoids after the thiophilic attack onto the C = S bond undergo competitive 1,3- versus 1,5-dipolar electrocyclization leading to Thiiranes or 1,3-oxathioles, respectively. From the point of view of potential practical applications (coordination chemistry, organometallic chemistry, polymer chemistry), zwitterionic hetarylidene dithiocarboxylates accessible as stable 1:1 adducts from the reactions of nucleophilic heterocyclic carbenes (NHCs) with carbon disulfide are of great interest
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A DFT Study on the Barton–Kellogg Reaction – The Molecular Mechanism of the Formation of Thiiranes in the Reaction between Diphenyldiazomethane and Diaryl Thioketones
'Wiley', 2020Co-Authors: Mlostoń Grzegorz, Jasinski Radomir, Kula Karolina, Heimgartner HeinzAbstract:The mechanism of the reaction of diphenyldiazomethane with thiobenzophenone and related hetaryl thioketones leading to the corresponding tetrasubstituted Thiiranes was studied by means of DFT computational methods at the M06-2X/6-311+G(d) level of theory. The study showed that the initial step of this conversion is a classic one-step (3+2) cycloaddition to give 1,3,4-thiadiazolines in a regioselective manner. These initially formed products undergo a spontaneous extrusion of N2 resulting in the formation of tetraaryl-substituted thiocarbonyl ylides as reactive intermediates. The calculated parameters of the activation for the subsequent 1,3-dipolar electrocyclizations are low (ΔG = 10.8–11.9 kcal/mol) and the only products formed in these reactions are the corresponding Thiiranes. The alternative pathways leading to thiocarbonyl ylides via stepwise mechanisms involving zwitterionic or biradical nitrogen-containing intermediates were ruled out
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New applications of hetaryl thioketones for the synthesis of hetaryl-substituted ethenes via ‘two-fold extrusion reaction‘
'Japan Institute of Heterocyclic Chemistry', 2016Co-Authors: Mlostoń Grzegorz, Urbaniak Katarzyna, Pawlak Aneta, Heimgartner HeinzAbstract:A series of aryl/hetaryl thioketones was applied for the reactions with aryl/hetaryldiazomethanes yielding, after elimination of N2, the corresponding Thiiranes. The relatively unstable dihetaryldiazomethanes were generated in situ from the corresponding hydrazones by oxidation with DMSO. The obtained Thiiranes were converted into tetraaryl/hetaryl-substituted ethenes in good yields by desulfurization performed with tris(diethylamino)phosphine ((Et2N)3P)
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Synthesis of ferrocenyl thioketones and their reactions with diphenyldiazomethane
Taylor & Francis, 2015Co-Authors: Mlostoń Grzegorz, Hamera Roza, Heimgartner HeinzAbstract:A series of ferrocenyl ketones was obtained via Friedel-Crafts acylation with mixed anhydrides using ferrocene as a nucleophilic agent or ferrocene carboxylic acid as a precursor of the electrophilic species. The ketones obtained thereby undergo smooth thionation (THF, 65 ºC) with Lawesson’s reagent. The ferrocenyl thioketones react with diphenyldiazomethane via N2 elimination to afford the hitherto unknown ferrocenyl-substituted Thiiranes
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Reactions of alpha-diazocamphor with aromatic thioketones
'Japan Institute of Heterocyclic Chemistry', 2006Co-Authors: Mlostoń Grzegorz, Celeda Malgorzata, Linden Anthony, Heimgartner HeinzAbstract:The reactions of α-diazocamphor (6) with aromatic thioketones (9a-d) in dichloromethane at room temperature afforded mixtures of the stereoisomeric spirocyclic Thiiranes (10) and (11). A reaction mechanism via [2+3] cycloaddition to give the spirocyclic 2,5-dihydro-1,3,4-thiadiazoles (13) and (14), subsequent elimination of nitrogen and 1,3-dipolar electrocyclization of the intermediate thiocarbonyl ylide (15) is proposed. The structure of the stereoisomers (10a) and (11a) has been established by X-Ray crystallography. Desulfurization of the mixtures (10/11) with triphenylphosphane in boiling THF yielded the alkylidene derivatives (12)
A C Legon - One of the best experts on this subject based on the ideXlab platform.
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nature and angular geometry of the pre reactive complex thiirane chlorine monofluoride from its rotational spectrum
Chemical Physics Letters, 1996Co-Authors: C M Evans, John H Holloway, A C LegonAbstract:Abstract The rotational spectrum of the pre-reactive complex thiirane-ClF was detected with a fast-mixing nozzle in an FT microwave spectrometer. Rotational constants, centrifugal distortion constants, Cl-nuclear quadrupole and spin-rotation coupling constants were determined for the isotopomers (CH 2 ) 2 S… 35 ClF and (CH 2 ) 2 S… 37 ClF. The complex has C s symmetry, with a nearly collinear arrangement of the S…ClF nuclei ( σ ≈3.5°) and the ClF axis making an angle φ =95° with the C 2 axis of thiirane. The Cl-nuclear quadrupole coupling constant χ zz along the ClF internuclear axis suggests a significant contribution of the ionic structure [(CH 2 ) 2 SCl] + …F − to a valence-bond description of the complex.
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pre chemical interactions in a pulsed jet the angular geometry of thiirane hcl and the nonlinearity of its hydrogen bond from rotational spectroscopy
Principles and Practice of Constraint Programming, 1995Co-Authors: C M Evans, A C LegonAbstract:Abstract Ground-state rotational spectra of three isotopomers, (CH2)232S ⋯ H35Cl, (CH2)232S ⋯ H37Cl, and (CH2)234S ⋯ H35Cl, of a complex formed by hydrogen chloride and the three-membered S-containing ring thiirane were observed by pulsed-nozzle, Fourier-transform microwave spectroscopy. A fast-mixing nozzle was used to keep the components separate until they expanded coaxially into the Fabry-Perot cavity and to preclude a chemical reaction. Spectral analysis gave rotational constants, centrifugal distortion constants and the complete Cl-nuclear quadrupole coupling tensor (χaa, χbb−χcc and χab) for each isotopomer. For (CH2)232S ⋯ H35Cl, the components Maa and Tr(M) of the Cl-spin-rotation tensor were also determined. The off-diagonal nuclear quadrupole coupling constant χab led to a good approximation to the equilibrium angle αaz between the directions of the HCl axis (z) and the a-principal inertial axis. The complex was established to have Cs symmetry and then its detailed angular geometry was determined by fitting the moments of inertia and the angle αaz. It was found that the angle between the thiirane C2 axis and the S ⋯ H bond direction was Φ = 85.5 (20)°, the distance r( S ⋯ H ) = 2.329(28) A and the deviation of the hydrogen bons S ⋯ HCl from collinearity was δ = 21.0(5)°. These results are rationalised in terms of a simple model for predicting angular geometrics in which the primary hydrogen bond is made by HCl with the thiirane S atom, while a secondary hydrogen bond involving the thiirane CH2 groups and the Cl atom is responsible for the nonlinearity of the primary interaction.
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secondary interactions in weakly bound complexes a highly nonlinear hydrogen bond in thiirane hcn established by rotational spectroscopy
Chemical Physics Letters, 1994Co-Authors: Jean Cosleou, David G. Lister, A C LegonAbstract:Abstract The ground-state rotational spectra of two isotopomers, (CH 2 ) 2 32 S·HC 14 N and (CH 2 ) 2 32 S·HC 15 N, of a complex formed by thiirane with hydrogen cyanide were analysed to give rotational constants, centrifugal distortion constants and 14 N-nuclear quadrupole coupling constants. The spectroscopic constants were interpreted in terms of a geometry of the complex characterised by the angle φ = 89.2(9)° made by the S·H internuclear axis with the thiirane heavy atom plane at S and a nonlinearity θ≈43° of the S·H-C hydrogen bond. This large nonlinearity is contrasted with that in (CH 2 ) 2 O·HCN and the difference discussed in terms of a simple model of the hydrogen bond.
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the rotational spectrum of the argon thiirane van der waals molecule
Chemical Physics Letters, 1992Co-Authors: A C Legon, David G. ListerAbstract:Abstract The rotational spectrum of the argon—thiirane van der Waals molecule has been observed using pulsed-nozzle, Fourier-transform microwave spectroscopy. Transitions due to μa and μb components of the electric dipole moment have been observed and used to derive rotational and quartic centrifugal distortion constants. The molecule has Cs symmetry with a distance R = 3.79 pm from the centre of mass of thiirane to the argon atom and an angle θ = 98° between this vector and the bisector of the CSC bond angle of the thiirane molecule. An upper limit of 10 kHz is placed on the ground vibrational state inversion frequency in Ar…S(CH2)2.
Mlostoń Grzegorz - One of the best experts on this subject based on the ideXlab platform.
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A DFT Study on the Barton–Kellogg Reaction – The Molecular Mechanism of the Formation of Thiiranes in the Reaction between Diphenyldiazomethane and Diaryl Thioketones
'Wiley', 2020Co-Authors: Mlostoń Grzegorz, Jasinski Radomir, Kula Karolina, Heimgartner HeinzAbstract:The mechanism of the reaction of diphenyldiazomethane with thiobenzophenone and related hetaryl thioketones leading to the corresponding tetrasubstituted Thiiranes was studied by means of DFT computational methods at the M06-2X/6-311+G(d) level of theory. The study showed that the initial step of this conversion is a classic one-step (3+2) cycloaddition to give 1,3,4-thiadiazolines in a regioselective manner. These initially formed products undergo a spontaneous extrusion of N2 resulting in the formation of tetraaryl-substituted thiocarbonyl ylides as reactive intermediates. The calculated parameters of the activation for the subsequent 1,3-dipolar electrocyclizations are low (ΔG = 10.8–11.9 kcal/mol) and the only products formed in these reactions are the corresponding Thiiranes. The alternative pathways leading to thiocarbonyl ylides via stepwise mechanisms involving zwitterionic or biradical nitrogen-containing intermediates were ruled out
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Reactions of thiocarbonyl compounds with electrophilic and nucleophilic carbenes as well as with their metal complexes
'Informa UK Limited', 2020Co-Authors: Mlostoń Grzegorz, Heimgartner HeinzAbstract:A variety of cyclic and acyclic products are reported for reactions of thiocarbonyl compounds with carbenes and their metal complexed derivatives. Electrophilic and nucleophilic carbenes react with non-enolizable thioketones yielding thiocarbonyl ylides or 1,3-zwitterions, respectively, as plausible, reactive intermediates. In most cases, the initially formed intermediates undergo 1,3- electrocyclization yielding respective Thiiranes, which, depending on the substitution pattern, are either isolated as final products or extrude elemental sulfur forming substituted ethylene derivatives. In addition, reactive thiocarbonyl ylides formed from α-oxo substituted carbenoids after the thiophilic attack onto the C = S bond undergo competitive 1,3- versus 1,5-dipolar electrocyclization leading to Thiiranes or 1,3-oxathioles, respectively. From the point of view of potential practical applications (coordination chemistry, organometallic chemistry, polymer chemistry), zwitterionic hetarylidene dithiocarboxylates accessible as stable 1:1 adducts from the reactions of nucleophilic heterocyclic carbenes (NHCs) with carbon disulfide are of great interest
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New applications of hetaryl thioketones for the synthesis of hetaryl-substituted ethenes via ‘two-fold extrusion reaction‘
'Japan Institute of Heterocyclic Chemistry', 2016Co-Authors: Mlostoń Grzegorz, Urbaniak Katarzyna, Pawlak Aneta, Heimgartner HeinzAbstract:A series of aryl/hetaryl thioketones was applied for the reactions with aryl/hetaryldiazomethanes yielding, after elimination of N2, the corresponding Thiiranes. The relatively unstable dihetaryldiazomethanes were generated in situ from the corresponding hydrazones by oxidation with DMSO. The obtained Thiiranes were converted into tetraaryl/hetaryl-substituted ethenes in good yields by desulfurization performed with tris(diethylamino)phosphine ((Et2N)3P)
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Synthesis of ferrocenyl thioketones and their reactions with diphenyldiazomethane
Taylor & Francis, 2015Co-Authors: Mlostoń Grzegorz, Hamera Roza, Heimgartner HeinzAbstract:A series of ferrocenyl ketones was obtained via Friedel-Crafts acylation with mixed anhydrides using ferrocene as a nucleophilic agent or ferrocene carboxylic acid as a precursor of the electrophilic species. The ketones obtained thereby undergo smooth thionation (THF, 65 ºC) with Lawesson’s reagent. The ferrocenyl thioketones react with diphenyldiazomethane via N2 elimination to afford the hitherto unknown ferrocenyl-substituted Thiiranes
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Reactions of alpha-diazocamphor with aromatic thioketones
'Japan Institute of Heterocyclic Chemistry', 2006Co-Authors: Mlostoń Grzegorz, Celeda Malgorzata, Linden Anthony, Heimgartner HeinzAbstract:The reactions of α-diazocamphor (6) with aromatic thioketones (9a-d) in dichloromethane at room temperature afforded mixtures of the stereoisomeric spirocyclic Thiiranes (10) and (11). A reaction mechanism via [2+3] cycloaddition to give the spirocyclic 2,5-dihydro-1,3,4-thiadiazoles (13) and (14), subsequent elimination of nitrogen and 1,3-dipolar electrocyclization of the intermediate thiocarbonyl ylide (15) is proposed. The structure of the stereoisomers (10a) and (11a) has been established by X-Ray crystallography. Desulfurization of the mixtures (10/11) with triphenylphosphane in boiling THF yielded the alkylidene derivatives (12)
Oscar N Ventura - One of the best experts on this subject based on the ideXlab platform.
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isomerization and fragmentation reactions on the c2sh4 potential energy surface the metastable thione s methylide isomer
Journal of Organic Chemistry, 2021Co-Authors: Zoi Salta, Marc E Segovia, Aline Katz, Nicola Tasinato, Vincenzo Barone, Oscar N VenturaAbstract:Thione S-methylide, parent species of the thiocarbonyl ylide family, is a 1,3-dipolar species on the [C2SH4] potential energy surface, not so much studied as its isomers, thiirane, vinyl thiol, and...
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isomerization and fragmentation reactions on the c2sh4 potential energy surface the metastable thione s methylide isomer
ChemRxiv, 2020Co-Authors: Zoi Salta, Marc E Segovia, Aline Katz, Nicola Tasinato, Vincenzo Barone, Oscar N VenturaAbstract:Thione S-methylide (TSM), the parent species of the thiocarbonyl ylide family, is a 1,3-dipolar, planar species on the [C2SH4] potential energy surface (PES), which has not shared the richness of studies dedicated to its isomers, the cyclic thiirane (THI), and the keto-enol pair vinyl thiol (VTH)/thioacetaldehyde (THA). While the conrotatory ring closure reaction toward THI was studied in the ‘90s, no complete analysis of the PES is available in the literature. In the present paper, we report a computational study of the reaction scheme linking all species on that PES. We employ several levels of calculation, ranging from density functional theory (DFT), through CCSD(T) based composite schemes, to CASSCF/CASPT2 multi-reference procedures, to find the best description of TSM, its isomers, and the transition states (TSs) ruling their interconversion. Fragmentation of TSM, THA and THI were investigated and compared to the available experimental information. We found that the B2PLYP-D3 functional, contrary to M06-2XD3 or B97X-D, describes well the geometry of both TSM and the transition state connecting it to THI. The reverse barrier, from THI to TSM, amounts to 52.2 kcal mol-1 (to be compared to 17.6 kcal mol-1 for the direct one), thus explaining why, in general, thiocarbonyl ylides cannot be prepared from Thiiranes. Conversion of THI to VTH implies also a large barrier, explaining why the reaction has been observed only at high temperatures. The fragmentation of THI to S(3P) or S(1D) and ethylene was also explored, together with the decomposition to H2S plus acetylene. Open species, both in triplet and singlet states, were identified as intermediates in the fragmentations, and their energies were found to be lower than the transition state for the isomerization of THI to VTH, thus explaining the preference for fragmentation over isomerization at relatively low temperatures.
Grzegorz Mloston - One of the best experts on this subject based on the ideXlab platform.
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a dft study on the barton kellogg reaction the molecular mechanism of the formation of Thiiranes in the reaction between diphenyldiazomethane and diaryl thioketones
European Journal of Organic Chemistry, 2020Co-Authors: Grzegorz Mloston, Radomir Jasinski, Karolina Kula, Heinz HeimgartnerAbstract:The mechanism of the reaction of diphenyldiazomethane with thiobenzophenone and related hetaryl thioketones leading to the corresponding tetrasubstituted Thiiranes was studied by means of DFT computational methods at the M06-2X/6-311+G(d) level of theory. The study showed that the initial step of this conversion is a classic one-step (3+2) cycloaddition to give 1,3,4-thiadiazolines in a regioselective manner. These initially formed products undergo a spontaneous extrusion of N2 resulting in the formation of tetraaryl-substituted thiocarbonyl ylides as reactive intermediates. The calculated parameters of the activation for the subsequent 1,3-dipolar electrocyclizations are low (ΔG = 10.8–11.9 kcal/mol) and the only products formed in these reactions are the corresponding Thiiranes. The alternative pathways leading to thiocarbonyl ylides via stepwise mechanisms involving zwitterionic or biradical nitrogen-containing intermediates were ruled out.
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1 3 oxathiole and thiirane derivatives from the reactions of azibenzil and α diazo amides with thiocarbonyl compounds
Helvetica Chimica Acta, 1998Co-Authors: Martin Kagi, Anthony Linden, Grzegorz MlostonAbstract:The reactions of alpha-diazoketones la,b with 9H-fluorene-9-thione (2f) in THF at room temperature yielded the symmetrical l,3-dithiolanes 7a,b, whereas lb and 2,2,4,4-tetramethylcyclobutane-1,3-dithione (2d) in THF at 60' led to a mixture of two stereoisomeric 1,3-oxathiole derivatives cis- and trans-9a (Scheme 2). With 2-diazo-1,2-diphenylethanone (lc), thioketones 2a-d as well as 1,3-thiazole-5(4H)-thione 2g reacted to give 1,3-oxathiole derivatives exclusively (Schemes 3 and 4). As the reactions with lc were more sluggish than those with la,b, they were catalyzed either by the addition of LiCIO4, or by Rh2(OAc)4. In the case of 2d in THF/LiCIO4 at room temperature, a mixture of the monoadduct 4d and the stereoisomeric bis-adducts cis- and trans-9b was formed. Monoadduct 4d could be transformed to cis- and rrans-9b by treatment with lc in the presence of Rh2(OAc)4 (Scheme 4). Xanthione (2e) and lc in THF at room temperature reacted only when catalyzed with Rh2(OAc)4, and, in contrast to the previous reactions, the benzoyl-substituted thiirane derivative 5a was the sole product (Scheme 4). Both types of reaction were observed with alpha-diazo amides ld,e (Schemes 5-7). It is worth mentioning that formation of I,3-oxathiole or thiirane is not only dependent on the type of the carbonyl compound 2 but also on the alpha-diazo amide. In the case of Id and thioxocyclobutanone 2c in THF at room temperature, the primary cycloadduct 12 was the main product. Heating the mixture to 60", 1,3-oxathiole 10d as well as the spirocyclic thiirane-carboxamide11lb were formed. Thiirane-carboxamides 11d - g were desulfurized with (Me2N)3P in THF at 60", yielding the corresponding acrylamide derivatives (Scheme 7). All reactions are rationalized by a mecha- nism via initial formation of acyl-substituted thiocarbonyl ylides which undergo either a 1,5-dipolar electrocyclization to give 1,3-oxathiole derivatives or a I,3-dipolar electrocyclization to yield Thiiranes. Only in the case of the most reactive 9H-fluorene-9-thione (2f) is the thiocarbonyl ylide trapped by a second molecule of 2f to give I,3-dithiolane derivatives by a 1,3-dipolar cycloaddition.