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Grzegorz Mlostoń - One of the best experts on this subject based on the ideXlab platform.
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A DFT Study on the Molecular Mechanism of Additions of Electrophilic and Nucleophilic Carbenes to Non-Enolizable Cycloaliphatic Thioketones
'MDPI AG', 2021Co-Authors: Grzegorz Mlostoń, Karolina Kula, Radomir JasińskiAbstract:The molecular mechanisms of addition of dihalocarbenes and dimethoxycarbene to Thioketones derived from 2,2,4,4-tetrmethylcyclobutane-1,3-dione were examined on the basis of the DFT wb97xd/6-311g(d,p)(PCM) calculations. Obtained results demonstrated that the examined processes exhibit polar nature and in the case of electrophilic dichloro-, and dibromocarbenes are initiated by the attack of carbene species onto the sulfur atom of the C=S group. Remarkably, reactions involving more electrophilic carbenes (dichloro-, and dibromocarbene) proceeds via stepwise mechanism involving thiocarbonyl ylide as a transient intermediate. In contrast, analogous reactions with nucleophilic dimethoxycarbene occur via a single step reaction, which can be considered as the [2 + 1] cycloaddition reaction initiated by the attack onto the C=S bond. A computational study showed that difluorocarbene tends to react as a nucleophilic species and resembles rather dimethoxycarbene and not typical dihalocarbene species. Significantly higher reactivity of the thioketone unit in comparison to the ketone group, both present in 3-thioxo-2,2,4,4-tetramthylcyclobutanone molecule, was rationalized in the light of DFT computational study
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Ferrocenyl-substituted tetrahydrothiophenes via formal [3 + 2]-cycloaddition reactions of ferrocenyl Thioketones with donor-acceptor cyclopropanes.
Beilstein Journal of Organic Chemistry, 2020Co-Authors: Grzegorz Mlostoń, Mateusz Kowalczyk, André U. Augustin, Peter G. Jones, Daniel B. WerzAbstract:Ferrocenyl Thioketones reacted with donor-acceptor cyclopropanes in dichloromethane at room temperature in the presence of catalytic amounts of Sc(OTf)3 yielding tetrahydrothiophene derivatives, products of formal [3 + 2]-cycloaddition reactions, in moderate to high yields. In all studied cases, dimethyl 2-arylcyclopropane dicarboxylates reacted with the corresponding aryl ferrocenyl Thioketones in a completely diastereoselective manner to form single products in which (C-2)-Ar and (C-5)-ferrocenyl groups were oriented in a cis-fashion. In contrast, the same cyclopropanes underwent reaction with alkyl ferrocenyl Thioketones to form nearly equal amounts of both diastereoisomeric tetrahydrothiophenes. A low selectivity was also observed in the reaction of a 2-phthalimide-derived cyclopropane with ferrocenyl phenyl thioketone.
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ferrocenyl substituted tetrahydrothiophenes via formal 3 2 cycloaddition reactions of ferrocenyl Thioketones with donor acceptor cyclopropanes
Beilstein Journal of Organic Chemistry, 2020Co-Authors: Grzegorz Mlostoń, Mateusz Kowalczyk, André U. Augustin, Peter G. Jones, Daniel B. WerzAbstract:Ferrocenyl Thioketones reacted with donor-acceptor cyclopropanes in dichloromethane at room temperature in the presence of catalytic amounts of Sc(OTf)3 yielding tetrahydrothiophene derivatives, products of formal [3 + 2]-cycloaddition reactions, in moderate to high yields. In all studied cases, dimethyl 2-arylcyclopropane dicarboxylates reacted with the corresponding aryl ferrocenyl Thioketones in a completely diastereoselective manner to form single products in which (C-2)-Ar and (C-5)-ferrocenyl groups were oriented in a cis-fashion. In contrast, the same cyclopropanes underwent reaction with alkyl ferrocenyl Thioketones to form nearly equal amounts of both diastereoisomeric tetrahydrothiophenes. A low selectivity was also observed in the reaction of a 2-phthalimide-derived cyclopropane with ferrocenyl phenyl thioketone.
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structure of diferrocenyl thioketone from molecule to crystal
Molecules, 2019Co-Authors: Piotr Matczak, Grzegorz Mlostoń, Roza Hamerafaldyga, Helmar Gorls, Wolfgang WeigandAbstract:Ferrocenyl-functionalized Thioketones have recently been recognized as useful building blocks for sulfur-containing compounds with potential applications in materials chemistry. This work is devoted to a single representative of such Thioketones, namely diferrocenyl thioketone (Fc2CS), whose structure has been determined here for the first time. Both X-ray crystallography and a wide variety of quantum-chemical methods were used to explore the structure of Fc2CS. In addition to the X-ray structure determination, intermolecular interactions occurring in the crystal structure of Fc2CS were examined in detail by quantum-chemical methods. These methods were also an invaluable tool in studying the molecular structure of Fc2CS, from the gas phase to solutions and to its crystal. Intramolecular interactions governing the conformational behavior of an isolated Fc2CS molecule were deduced from quantum-chemical analyses carried out in orbital space and real space. Our experimental and theoretical results indicate that the main structural features of an isolated Fc2CS molecule in its lowest-energy geometry are retained both upon solvation and in the crystal. The tilt of ferrocenyl groups is only slightly affected by crystal packing forces that are dominated by dispersion. Nonetheless, a network of intermolecular interactions, such as H···H, C···H and S···H, was detected in the Fc2CS crystal but each of them is fairly weak.
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diferrocenyl thioketone reactions with bisphosphane pt 0 complexes electrochemical and computational studies
Materials, 2019Co-Authors: Sebastian Grober, Grzegorz Mlostoń, Piotr Matczak, Helmar Gorls, Slawomir Domagala, Thomas Weisheit, Annika Duver, Wolfgang WeigandAbstract:Diferrocenyl thioketone reacts smoothly with (bisphosphane)Pt(0) complexes in toluene solution at room temperature yielding 1:1 adducts identified as ferrocenyl (Fc) functionalized platinathiiranes. Their structures were unambiguously confirmed by means of spectroscopic methods as well as by X-ray diffraction analysis. A unique, ferrocene-rich platinathiirane, bearing three Fc-units, was prepared starting with [bis(diphenylphosphino)ferrocene] Pt(0(η2-norbornene). For comparison, a similar platinathiirane with one Fc-unit was obtained from the reaction of the latter complex with thiobenzophenone. Quantum-chemical calculations were carried out to describe the bonding pattern and frontier molecular orbitals of the ferrocene-rich platinathiirane complexes. These calculations confirmed that the C=S bond loses its formally double-bond character upon complexation (bisphosphane)Pt(0). Cyclic voltammetry measurements were performed to characterize the obtained platinathiiranes in CH2Cl2 solutions. For comparison, the cyclic voltammogram for diferrocenyl thioketoneas a mixed-valent (FeII-FeIII) compound was also recorded and analyzed. The results point out to a diffusion controlled electrode process in case of differocenyl thioketone and mixed diffusion and adsorption controlled electrode process in the case of the studied platinathiiranes.
Heinz Heimgartner - One of the best experts on this subject based on the ideXlab platform.
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a convenient access to 1 2 diferrocenyl substituted ethylenes via 3 2 cycloelimination of 2 silylated 4 4 5 5 tetrasubstituted 1 3 dithiolanes
Journal of Sulfur Chemistry, 2018Co-Authors: Grzegorz Mlostoń, Roza Hamerafaldyga, Katarzyna Urbaniak, Wolfgang Weigand, Heinz HeimgartnerAbstract:Ferrocenyl Thioketones bearing a hetaryl, phenyl or alkyl group as the second substituent react with (trimethylsilyl)diazomethane at ca. −30°C in THF solution without formation of a stable [3 + 2]-...
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a novel application of 2 silylated 1 3 dithiolanes for the synthesis of aryl hetaryl substituted ethenes and dibenzofulvenes
Beilstein Journal of Organic Chemistry, 2017Co-Authors: Grzegorz Mlostoń, Paulina Pipiak, Roza Hamerafaldyga, Heinz HeimgartnerAbstract:Trimethylsilyldiazomethane (TMS-CHN2) reacts readily with hetaryl Thioketones to give sterically crowded 2-trimethylsilyl-4,4,5,5-tetrahetaryl-1,3-dithiolanes with complete regioselectivity at −75 °C as well as at rt. Thiofluorenone, a relatively stable and highly reactive aryl thioketone, yields upon treatment with TMS-CHN2 at −60 °C the corresponding 1,3,4-thiadiazoline. This unstable cycloadduct undergoes decomposition at ca. −45 °C and the silylated thiocarbonyl S-methanide generated thereby is trapped with complete regioselectivity by aryl or hetaryl Thioketones forming also sterically crowded 2-trimethylsilyl-1,3-dithiolanes. The obtained 1,3-dithiolanes, by treatment with an equimolar amount of TBAF in a one-pot procedure, are converted in high yields into hetaryl/aryl-substituted ethenes or dibenzofulvenes, respectively, via a cycloreversion reaction of the intermediate 1,3-dithiolane carbanion. The presented protocol offers a new, highly efficient approach to tetrasubstituted ethenes and dibenzofulvenes bearing aryl and/or hetaryl substituents.
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generation and reactions of thiocarbonyl s 2 2 2 trifluoroethanides synthesis of trifluoromethylated 1 3 dithiolanes thiiranes and alkenes
Journal of Fluorine Chemistry, 2017Co-Authors: Marcin K Kowalski, Grzegorz Mlostoń, Emilia Obijalska, Heinz HeimgartnerAbstract:Abstract The ‘in situ’ generated 1,1,1-trifluorodiazoethane reacts with Thioketones as C=S dipolarophiles in a two-phase system (DCM/H2O) at room temperature to yield trifluoromethylated 2,5-dihydro-1,3,4-thiadiazoles. Whereas stable crystalline products were obtained with cyclobutanethiones, the reaction with aromatic and heteroaromatic Thioketones occured with spontaneous elimination of nitrogen. The formation of sterically crowded 4,4,5,5-tetrahetaryl-1,3-dithiolanes indicates that thiocarbonyl S-methanides are formed immediately and entered formal [3+2]-cycloaddition as diradical species with the starting thioketone. A protocol for the preparation of 3,3,3-trifluoropropene derivatives starting from corresponding Thioketones and 1,1,1-trifluorodiazoethane is also presented.
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A novel application of 2-silylated 1,3-dithiolanes for the synthesis of aryl/hetaryl-substituted ethenes and dibenzofulvenes
Beilstein-Institut, 2017Co-Authors: Grzegorz Mlostoń, Paulina Pipiak, Róża Hamera-fałdyga, Heinz HeimgartnerAbstract:Trimethylsilyldiazomethane (TMS-CHN2) reacts readily with hetaryl Thioketones to give sterically crowded 2-trimethylsilyl-4,4,5,5-tetrahetaryl-1,3-dithiolanes with complete regioselectivity at −75 °C as well as at rt. Thiofluorenone, a relatively stable and highly reactive aryl thioketone, yields upon treatment with TMS-CHN2 at −60 °C the corresponding 1,3,4-thiadiazoline. This unstable cycloadduct undergoes decomposition at ca. −45 °C and the silylated thiocarbonyl S-methanide generated thereby is trapped with complete regioselectivity by aryl or hetaryl Thioketones forming also sterically crowded 2-trimethylsilyl-1,3-dithiolanes. The obtained 1,3-dithiolanes, by treatment with an equimolar amount of TBAF in a one-pot procedure, are converted in high yields into hetaryl/aryl-substituted ethenes or dibenzofulvenes, respectively, via a cycloreversion reaction of the intermediate 1,3-dithiolane carbanion. The presented protocol offers a new, highly efficient approach to tetrasubstituted ethenes and dibenzofulvenes bearing aryl and/or hetaryl substituents
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Efficient synthesis of fluoroalkylated 1,4,2-oxathiazoles via regioselective [3 + 2]-cycloaddition of fluorinated nitrile oxides with Thioketones
Journal of Fluorine Chemistry, 2017Co-Authors: Grzegorz Mlostoń, Marcin K Kowalski, Emilia Obijalska, Heinz HeimgartnerAbstract:Abstract Fluorinated acetonitrile oxides, generated from the corresponding hydroximoyl bromides in the presence of aryl, hetaryl, ferrocenyl, and cycloaliphatic Thioketones, undergo efficient [3 + 2]-cycloadditions to give 3-fluoroalkylated 1,4,2-oxathiazoles in good to excellent yields. The reactions proceed regioselectively with no competitive formation of furoxans as dimers of the intermediate 1,3-dipoles.
Heimgartner Heinz - One of the best experts on this subject based on the ideXlab platform.
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Hetero-Diels-Alder Reactions of In Situ-Generated Azoalkenes with Thioketones; Experimental and Theoretical Studies
'MDPI AG', 2021Co-Authors: Mlostoń Grzegorz, Heimgartner Heinz, Urbaniak Katarzyna, Zimmer Reinhold, Sobiecka Malwina, Würthwein Ernst-ulrich, Lentz Dieter, Reissig Hans-ulrichAbstract:The hetero-Diels-Alder reactions of in situ-generated azoalkenes with Thioketones were shown to offer a straightforward method for an efficient and regioselective synthesis of scarcely known N-substituted 1,3,4-thiadiazine derivatives. The scope of the method was fairly broad, allowing the use of a series of aryl-, ferrocenyl-, and alkyl-substituted Thioketones. However, in the case of N-tosyl-substituted cycloadducts derived from 1-thioxo-2,2,4,4-tetramethylcyclobutan-3-one and the structurally analogous 1,3-dithione, a more complicated pathway was observed. By elimination of toluene sulfinic acid, the initially formed cycloadducts afforded 2H-1,3,4-thiadiazines as final products. Advanced DFT calculations revealed that the observed high regioselectivity was due to kinetic reaction control and that the (4 + 2)-cycloadditions of sterically less unhindered thiones occurred via highly unsymmetric transition states with shorter C..S-distances (2.27–2.58 Å) and longer N..C-distances (3.02–3.57 Å). In the extreme case of the sterically very hindered 2,2,4,4- tetramethylcyclobutan-1,3-dione-derived Thioketones, a zwitterionic intermediate with a fully formed C-S bond was detected, which underwent ring closure to the 1,3,4-thiadiazine derivative in a second step. For the hypothetical formation of the regioisomeric 1,2,3-thiadiazine derivatives, the DFT calculations proposed more symmetric transition states with considerably higher energies
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Microwave-assisted reactions of $\alpha$-diazoketones with hetaryl and ferrocenyl Thioketones
'Informa UK Limited', 2018Co-Authors: Mlostoń Grzegorz, Hamera-faldyga Roza, Urbaniak Katarzyna, Jeske Malgorzata, Godziszewska Magdalena, Heimgartner HeinzAbstract:Differently substituted hetaryl Thioketones react with less reactive diazoketones under MW irradiation in toluene solution. After only 2 min, the reactions were complete and, depending on the type of the used diazoketone, α,β-unsaturated ketones, acyl substituted thiiranes or 1,3-oxathiols were obtained as final products. In the case of azibenzil and di(thiophen-2-yl) thioketone, a new type of 1,5-dipolar electrocyclization of the intermediate thiocarbonyl ylide involving a thiophene ring led to a fused sulfur heterocycle. In contrast to hetaryl Thioketones, the ferrocenyl analogues decompose under MW irradiation. Alternatively they react with diazopropanone and 2-diazo-1-phenylethanone in boiling THF in the presence of LiClO4 to give α,β-unsaturated ketones as sole products. In these cases, the reactions require long reaction times
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Efficient synthesis of ferrocifens and other ferrocenyl-substituted ethylenes via a ‘sulfur approach’
'Royal Society of Chemistry (RSC)', 2018Co-Authors: Mlostoń Grzegorz, Hamera-faldyga Roza, Celeda Malgorzata, Heimgartner HeinzAbstract:Stable and non-odorous alkyl ferrocenyl Thioketones react with bis(4-methoxyphenyl)diazomethane according to the ‘two-fold extrusion’ reaction principles, and tetrasubstituted ethylenes obtained thereby can be demethylated to give (Fc,2OH)-ferrocifens in good yields. The method offers an alternative approach to this class of medically relevant compounds. A similar protocol with alkyl ferrocenyl Thioketones and selected diaryldiazomethanes leads to ferrocenyl-substituted ethylenes including dibenzofulvenes. These products are of potential interest for electrochemical and photophysical studies
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Aryl, hetaryl, and ferrocenyl Thioketones as versatile building blocks for exploration in the organic chemistry of sulfur
Taylor & Francis, 2017Co-Authors: Mlostoń Grzegorz, Hamera-faldyga Roza, Urbaniak Katarzyna, Pipiak Paulina, Jasiński Marcin, Grzelak Paulina, Albrecht Lukasz, Hejmanowska Joanna, Heimgartner HeinzAbstract:Methods for the synthesis of hetaryl and ferrocenyl Thioketones as well as applications of this class of organic sulfur compounds in the synthesis of both sulfur-containing and sulfur-free organic products are summarized. The most important applications relate to [2+2]-, [3+2]-, and [4+2]-cycloadditions. Aromatic Thioketones react with diazomethane at −70°C, and the formed 1,3,4-thiadiazolines can be used as convenient precursors of reactive thiocarbonyl S-methanides. In contrast, the hetaryl Thioketones do not form this type of cycloadducts. Reactions of hetaryl Thioketones with thiocarbonyl S-methanides are proposed to occur via a stepwise diradical mechanism. Aryl and hetaryl Thioketones react as prone heterodienophiles with cyclic and acyclic dienes. The first asymmetric synthesis of dihydrothiopyranes from aryl and hetaryl Thioketones was performed using a L-proline-derived organocatalyst. Hetaryl thiochalcones are useful heterodienes for the preparation of hetaryl-substituted dihydrothiopyrans
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[3+2]-Cycloadditions of nitrilimines with heteroaryl Thioketones
'Informa UK Limited', 2017Co-Authors: Ali, Korany A, Linden Anthony, Mlostoń Grzegorz, Urbaniak Katarzyna, Heimgartner HeinzAbstract:The in situ generated nitrilimines are trapped efficiently with heteroaryl Thioketones bearing thiophen-2-yl or selenophen-2-yl substituents. The exclusive products observed in these reactions are 2,3-dihydro-1,3,4-thiadiazoles formed via regioselective [3+2]-cycloaddition. Competitive head-to-tail dimerization of the intermediate 1,3-dipoles was not observed in any of the studied reactions
Mlostoń Grzegorz - One of the best experts on this subject based on the ideXlab platform.
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Hetero-Diels-Alder Reactions of In Situ-Generated Azoalkenes with Thioketones; Experimental and Theoretical Studies
'MDPI AG', 2021Co-Authors: Mlostoń Grzegorz, Heimgartner Heinz, Urbaniak Katarzyna, Zimmer Reinhold, Sobiecka Malwina, Würthwein Ernst-ulrich, Lentz Dieter, Reissig Hans-ulrichAbstract:The hetero-Diels-Alder reactions of in situ-generated azoalkenes with Thioketones were shown to offer a straightforward method for an efficient and regioselective synthesis of scarcely known N-substituted 1,3,4-thiadiazine derivatives. The scope of the method was fairly broad, allowing the use of a series of aryl-, ferrocenyl-, and alkyl-substituted Thioketones. However, in the case of N-tosyl-substituted cycloadducts derived from 1-thioxo-2,2,4,4-tetramethylcyclobutan-3-one and the structurally analogous 1,3-dithione, a more complicated pathway was observed. By elimination of toluene sulfinic acid, the initially formed cycloadducts afforded 2H-1,3,4-thiadiazines as final products. Advanced DFT calculations revealed that the observed high regioselectivity was due to kinetic reaction control and that the (4 + 2)-cycloadditions of sterically less unhindered thiones occurred via highly unsymmetric transition states with shorter C..S-distances (2.27–2.58 Å) and longer N..C-distances (3.02–3.57 Å). In the extreme case of the sterically very hindered 2,2,4,4- tetramethylcyclobutan-1,3-dione-derived Thioketones, a zwitterionic intermediate with a fully formed C-S bond was detected, which underwent ring closure to the 1,3,4-thiadiazine derivative in a second step. For the hypothetical formation of the regioisomeric 1,2,3-thiadiazine derivatives, the DFT calculations proposed more symmetric transition states with considerably higher energies
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Efficient synthesis of ferrocifens and other ferrocenyl-substituted ethylenes via a ‘sulfur approach’
'Royal Society of Chemistry (RSC)', 2018Co-Authors: Mlostoń Grzegorz, Hamera-faldyga Roza, Celeda Malgorzata, Heimgartner HeinzAbstract:Stable and non-odorous alkyl ferrocenyl Thioketones react with bis(4-methoxyphenyl)diazomethane according to the ‘two-fold extrusion’ reaction principles, and tetrasubstituted ethylenes obtained thereby can be demethylated to give (Fc,2OH)-ferrocifens in good yields. The method offers an alternative approach to this class of medically relevant compounds. A similar protocol with alkyl ferrocenyl Thioketones and selected diaryldiazomethanes leads to ferrocenyl-substituted ethylenes including dibenzofulvenes. These products are of potential interest for electrochemical and photophysical studies
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Microwave-assisted reactions of $\alpha$-diazoketones with hetaryl and ferrocenyl Thioketones
'Informa UK Limited', 2018Co-Authors: Mlostoń Grzegorz, Hamera-faldyga Roza, Urbaniak Katarzyna, Jeske Malgorzata, Godziszewska Magdalena, Heimgartner HeinzAbstract:Differently substituted hetaryl Thioketones react with less reactive diazoketones under MW irradiation in toluene solution. After only 2 min, the reactions were complete and, depending on the type of the used diazoketone, α,β-unsaturated ketones, acyl substituted thiiranes or 1,3-oxathiols were obtained as final products. In the case of azibenzil and di(thiophen-2-yl) thioketone, a new type of 1,5-dipolar electrocyclization of the intermediate thiocarbonyl ylide involving a thiophene ring led to a fused sulfur heterocycle. In contrast to hetaryl Thioketones, the ferrocenyl analogues decompose under MW irradiation. Alternatively they react with diazopropanone and 2-diazo-1-phenylethanone in boiling THF in the presence of LiClO4 to give α,β-unsaturated ketones as sole products. In these cases, the reactions require long reaction times
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[3+2]-Cycloadditions of nitrilimines with heteroaryl Thioketones
'Informa UK Limited', 2017Co-Authors: Ali, Korany A, Linden Anthony, Mlostoń Grzegorz, Urbaniak Katarzyna, Heimgartner HeinzAbstract:The in situ generated nitrilimines are trapped efficiently with heteroaryl Thioketones bearing thiophen-2-yl or selenophen-2-yl substituents. The exclusive products observed in these reactions are 2,3-dihydro-1,3,4-thiadiazoles formed via regioselective [3+2]-cycloaddition. Competitive head-to-tail dimerization of the intermediate 1,3-dipoles was not observed in any of the studied reactions
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Aryl, hetaryl, and ferrocenyl Thioketones as versatile building blocks for exploration in the organic chemistry of sulfur
Taylor & Francis, 2017Co-Authors: Mlostoń Grzegorz, Hamera-faldyga Roza, Urbaniak Katarzyna, Pipiak Paulina, Jasiński Marcin, Grzelak Paulina, Albrecht Lukasz, Hejmanowska Joanna, Heimgartner HeinzAbstract:Methods for the synthesis of hetaryl and ferrocenyl Thioketones as well as applications of this class of organic sulfur compounds in the synthesis of both sulfur-containing and sulfur-free organic products are summarized. The most important applications relate to [2+2]-, [3+2]-, and [4+2]-cycloadditions. Aromatic Thioketones react with diazomethane at −70°C, and the formed 1,3,4-thiadiazolines can be used as convenient precursors of reactive thiocarbonyl S-methanides. In contrast, the hetaryl Thioketones do not form this type of cycloadducts. Reactions of hetaryl Thioketones with thiocarbonyl S-methanides are proposed to occur via a stepwise diradical mechanism. Aryl and hetaryl Thioketones react as prone heterodienophiles with cyclic and acyclic dienes. The first asymmetric synthesis of dihydrothiopyranes from aryl and hetaryl Thioketones was performed using a L-proline-derived organocatalyst. Hetaryl thiochalcones are useful heterodienes for the preparation of hetaryl-substituted dihydrothiopyrans
Roza Hamerafaldyga - One of the best experts on this subject based on the ideXlab platform.
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structure of diferrocenyl thioketone from molecule to crystal
Molecules, 2019Co-Authors: Piotr Matczak, Grzegorz Mlostoń, Roza Hamerafaldyga, Helmar Gorls, Wolfgang WeigandAbstract:Ferrocenyl-functionalized Thioketones have recently been recognized as useful building blocks for sulfur-containing compounds with potential applications in materials chemistry. This work is devoted to a single representative of such Thioketones, namely diferrocenyl thioketone (Fc2CS), whose structure has been determined here for the first time. Both X-ray crystallography and a wide variety of quantum-chemical methods were used to explore the structure of Fc2CS. In addition to the X-ray structure determination, intermolecular interactions occurring in the crystal structure of Fc2CS were examined in detail by quantum-chemical methods. These methods were also an invaluable tool in studying the molecular structure of Fc2CS, from the gas phase to solutions and to its crystal. Intramolecular interactions governing the conformational behavior of an isolated Fc2CS molecule were deduced from quantum-chemical analyses carried out in orbital space and real space. Our experimental and theoretical results indicate that the main structural features of an isolated Fc2CS molecule in its lowest-energy geometry are retained both upon solvation and in the crystal. The tilt of ferrocenyl groups is only slightly affected by crystal packing forces that are dominated by dispersion. Nonetheless, a network of intermolecular interactions, such as H···H, C···H and S···H, was detected in the Fc2CS crystal but each of them is fairly weak.
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a convenient access to 1 2 diferrocenyl substituted ethylenes via 3 2 cycloelimination of 2 silylated 4 4 5 5 tetrasubstituted 1 3 dithiolanes
Journal of Sulfur Chemistry, 2018Co-Authors: Grzegorz Mlostoń, Roza Hamerafaldyga, Katarzyna Urbaniak, Wolfgang Weigand, Heinz HeimgartnerAbstract:Ferrocenyl Thioketones bearing a hetaryl, phenyl or alkyl group as the second substituent react with (trimethylsilyl)diazomethane at ca. −30°C in THF solution without formation of a stable [3 + 2]-...
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a novel application of 2 silylated 1 3 dithiolanes for the synthesis of aryl hetaryl substituted ethenes and dibenzofulvenes
Beilstein Journal of Organic Chemistry, 2017Co-Authors: Grzegorz Mlostoń, Paulina Pipiak, Roza Hamerafaldyga, Heinz HeimgartnerAbstract:Trimethylsilyldiazomethane (TMS-CHN2) reacts readily with hetaryl Thioketones to give sterically crowded 2-trimethylsilyl-4,4,5,5-tetrahetaryl-1,3-dithiolanes with complete regioselectivity at −75 °C as well as at rt. Thiofluorenone, a relatively stable and highly reactive aryl thioketone, yields upon treatment with TMS-CHN2 at −60 °C the corresponding 1,3,4-thiadiazoline. This unstable cycloadduct undergoes decomposition at ca. −45 °C and the silylated thiocarbonyl S-methanide generated thereby is trapped with complete regioselectivity by aryl or hetaryl Thioketones forming also sterically crowded 2-trimethylsilyl-1,3-dithiolanes. The obtained 1,3-dithiolanes, by treatment with an equimolar amount of TBAF in a one-pot procedure, are converted in high yields into hetaryl/aryl-substituted ethenes or dibenzofulvenes, respectively, via a cycloreversion reaction of the intermediate 1,3-dithiolane carbanion. The presented protocol offers a new, highly efficient approach to tetrasubstituted ethenes and dibenzofulvenes bearing aryl and/or hetaryl substituents.
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synthesis of ferrocenyl substituted 1 3 dithiolanes via 3 2 cycloadditions of ferrocenyl hetaryl Thioketones with thiocarbonyl s methanides
Beilstein Journal of Organic Chemistry, 2016Co-Authors: Grzegorz Mlostoń, Anthony Linden, Roza Hamerafaldyga, Heinz HeimgartnerAbstract:Ferrocenyl hetaryl Thioketones react smoothly with in situ generated thiocarbonyl S-methanides to give 1,3-dithiolanes. In the case of aromatic S-methanides, the sterically more crowded 4,4,5,5-tetrasubstituted 1,3-dithiolanes (2-CH2 isomers) were formed as sole products. The reactions with cycloaliphatic S-methanides led to mixtures of 2-CH2 and 5-CH2 isomers with the major component being the sterically more crowded 2-CH2 isomers. The preferred formation of the latter products is explained by the assumption that the formal [3 + 2]-cycloadducts were formed via a stepwise reaction mechanism with a stabilized 1,5-diradical as a key intermediate. The complete change of the reaction mechanism toward the concerted [3 + 2]-cycloaddition was observed in the reaction of a sterically crowded cycloaliphatic thiocarbonyl ylide with ferrocenyl methyl thioketone.
