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Viacheslav A. Petrov - One of the best experts on this subject based on the ideXlab platform.
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Simple synthesis of 1,1-bis(trifluoromethyl)cyclopropanes
Journal of Fluorine Chemistry, 2012Co-Authors: Viacheslav A. Petrov, Will MarshallAbstract:Abstract A new, simple synthesis of 1,1-bis(trifluoromethyl)cyclopropanes has been discovered. It is based on the reaction of readily available 2,2-bis(trifluoromethyl)Thietanes with tertiary phosphines in a polar solvent, which leads to an unusual desulfurization process, resulting in the formation of 1,1-bis(trifluoromethyl)-2-alkoxy cyclopropanes. The process of the corresponding Thietanes appears to be sensitive to the steric volume of the atom connected to carbon in α-position to sulfur.
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Remarkable effect of metal fluoride catalyst on reaction of hexafluoropropene, sulfur and vinyl ethers. Convenient synthesis of 2,2-bis(trifluoromethyl)-4-R-Thietanes, 3,3-bis(trifluoromethyl)-5-R-1,2-dithiolanes and 2,2-bis(trifluoromethyl)-4-R-1,3-
Journal of Fluorine Chemistry, 2010Co-Authors: Viacheslav A. Petrov, Will MarshallAbstract:Abstract It was demonstrated that the outcome of the reaction of hexafluoropropene, sulfur and vinyl ether strongly depends on the catalyst and reaction conditions. The reaction of HFP and Sx leading to the formation of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-diThietane (1) when it is catalyzed by CsF, proceeds under milder conditions and is easier to control compared to KF catalyzed process. The order of addition of reagents plays a crucial role on the outcome of the reaction. For example, the addition of vinyl ether to pregenerated solution of 1 in DMF solvent results in slow reaction, leading to the corresponding 2,2-bis(trifluoromethyl)-4-R-Thietanes in 8–91% yield, and it is catalyzed by either by KF or CsF. The addition of second mole of sulfur to the solution of 2,2-bis(trifluoromethyl)-4-R-Thietanes in the presence MF catalyst leads to insertion of sulfur into Thietane ring with the formation of the corresponding cyclic disulfides—3,3-bis(trifluoromethyl)-5-R-1,2-diThietanes. On the other hand, the addition of second mole of sulfur to the solution of 1 in DMF in the presence of CsF catalyst, followed by addition of vinyl ether results in exothermic reaction, and it produces the corresponding 2,2-bis(trifluoromethyl)-4-alkoxy-1,3-dithiolanes in good yield. It was also demonstrated that 2,2-bis(trifluoromethyl)-4-R-Thietanes can undergo disproportionation under action of fluoride anion, producing a mixture of the corresponding 1,2-dithiolane and CF2 C(CF3)CH2CFHOR. The nucleophilic attack of fluoride anion in this case proceeds selectively on the carbon of the Thietane ring, bearing alkoxy group. The structure of 2,2-bis(trifluoromethyl)-4-R-Thietanes forming as the result of 2 + 2 cycloaddition reaction between hexafluorothioacetone generated “in situ” from dimer 1 and vinyl ether was firmly supported by single crystal X-ray diffraction data, obtained for Thietane bearing t-BuO-group.
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Reactions of polyfluorinated Thietanes: Selective synthesis of 4-R-2,2-bis(trifluoromethyl)Thietane-1-S-oxides and 2-substituted 5-fluoro-4-(trifluoromethyl)-2,3-dihydrothiophenes
Journal of Fluorine Chemistry, 2009Co-Authors: Viacheslav A. Petrov, William J. MarshallAbstract:Abstract Oxidation of 4-substituted 2,2-bis(trifluoromethyl)Thietanes by m-chloroperoxybenzoic acid results in selective formation of the corresponding S-oxides in 65–86% yield. Oxidation of 4-C2H5S-2,2-bis(trifluoromethyl)Thietane under mild conditions led to selective formation of 4-C2H5SO2-2,2-bis(trifluoromethyl)Thietane, which under more rigorous conditions was selectively converted into trans-4-C2H5SO2-2,2-bis(trifluoromethyl)Thietane-1-S-oxide. Reaction of 4-substituted 2,2-bis(trifluoromethyl)Thietanes with activated aluminum powder results in a highly selective ring expansion process, producing the corresponding 5-fluoro-4-(trifluoromethyl)-2,3-dihydro-2-alkoxythiophenes in 58–93% yield. These compounds were also prepared in 61–85% yield using a “one-pot” procedure, starting from sulfur, hexafluoropropene and the corresponding vinyl ether without isolation of any intermediates. Both 2-i-C3H7O- and 2-t-C4H9O- 5-fluoro-4-(trifluoromethyl)-2,3-dihydrothiophenes were converted into 2-fluoro-3-trifluormethylthiophene by reaction with P2O5.
Will Marshall - One of the best experts on this subject based on the ideXlab platform.
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Simple synthesis of 1,1-bis(trifluoromethyl)cyclopropanes
Journal of Fluorine Chemistry, 2012Co-Authors: Viacheslav A. Petrov, Will MarshallAbstract:Abstract A new, simple synthesis of 1,1-bis(trifluoromethyl)cyclopropanes has been discovered. It is based on the reaction of readily available 2,2-bis(trifluoromethyl)Thietanes with tertiary phosphines in a polar solvent, which leads to an unusual desulfurization process, resulting in the formation of 1,1-bis(trifluoromethyl)-2-alkoxy cyclopropanes. The process of the corresponding Thietanes appears to be sensitive to the steric volume of the atom connected to carbon in α-position to sulfur.
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Remarkable effect of metal fluoride catalyst on reaction of hexafluoropropene, sulfur and vinyl ethers. Convenient synthesis of 2,2-bis(trifluoromethyl)-4-R-Thietanes, 3,3-bis(trifluoromethyl)-5-R-1,2-dithiolanes and 2,2-bis(trifluoromethyl)-4-R-1,3-
Journal of Fluorine Chemistry, 2010Co-Authors: Viacheslav A. Petrov, Will MarshallAbstract:Abstract It was demonstrated that the outcome of the reaction of hexafluoropropene, sulfur and vinyl ether strongly depends on the catalyst and reaction conditions. The reaction of HFP and Sx leading to the formation of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-diThietane (1) when it is catalyzed by CsF, proceeds under milder conditions and is easier to control compared to KF catalyzed process. The order of addition of reagents plays a crucial role on the outcome of the reaction. For example, the addition of vinyl ether to pregenerated solution of 1 in DMF solvent results in slow reaction, leading to the corresponding 2,2-bis(trifluoromethyl)-4-R-Thietanes in 8–91% yield, and it is catalyzed by either by KF or CsF. The addition of second mole of sulfur to the solution of 2,2-bis(trifluoromethyl)-4-R-Thietanes in the presence MF catalyst leads to insertion of sulfur into Thietane ring with the formation of the corresponding cyclic disulfides—3,3-bis(trifluoromethyl)-5-R-1,2-diThietanes. On the other hand, the addition of second mole of sulfur to the solution of 1 in DMF in the presence of CsF catalyst, followed by addition of vinyl ether results in exothermic reaction, and it produces the corresponding 2,2-bis(trifluoromethyl)-4-alkoxy-1,3-dithiolanes in good yield. It was also demonstrated that 2,2-bis(trifluoromethyl)-4-R-Thietanes can undergo disproportionation under action of fluoride anion, producing a mixture of the corresponding 1,2-dithiolane and CF2 C(CF3)CH2CFHOR. The nucleophilic attack of fluoride anion in this case proceeds selectively on the carbon of the Thietane ring, bearing alkoxy group. The structure of 2,2-bis(trifluoromethyl)-4-R-Thietanes forming as the result of 2 + 2 cycloaddition reaction between hexafluorothioacetone generated “in situ” from dimer 1 and vinyl ether was firmly supported by single crystal X-ray diffraction data, obtained for Thietane bearing t-BuO-group.
Miguel A Miranda - One of the best experts on this subject based on the ideXlab platform.
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Photoinduced Electron-Transfer Cycloreversion of Thietanes: The Role of Ion−Molecule Complexes
Organic Letters, 2010Co-Authors: Juan E Arguello, Raúl Pérez-ruiz, Miguel A MirandaAbstract:Cycloreversion (CR) of Thietane radical cations leads to formation of thiobenzophenone and the corresponding alkenes, eventually followed by secondary [4 + 2] cycloaddition. Final product distribution depends on the ability of fragments to escape from ion−molecule complexes (IMCs).
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Photoinduced electron-transfer cycloreversion of Thietanes: the role of ion-molecule complexes.
Organic letters, 2010Co-Authors: Juan E Arguello, Raúl Pérez-ruiz, Miguel A MirandaAbstract:Cycloreversion (CR) of Thietane radical cations leads to formation of thiobenzophenone and the corresponding alkenes, eventually followed by secondary [4 + 2] cycloaddition. Final product distribution depends on the ability of fragments to escape from ion−molecule complexes (IMCs).
Jan Cz. Dobrowolski - One of the best experts on this subject based on the ideXlab platform.
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Theoretical studies on the oxetane⋯HCl and Thietane⋯HCl complexes
Chemical Physics Letters, 2002Co-Authors: Joanna E. Rode, Jan Cz. DobrowolskiAbstract:Abstract The oxetane⋯HCl and Thietane⋯HCl complexes have recently been studied by rotational spectroscopy in a supersonic jet. In this Letter we report on stability, axial, and equatorial HCl arrangement in the complexes studied by means of MP2 calculations. The shape of the potential functions was studied for the ring-puckering and HCl inversion motions. For the oxetane complex, the barrier of the ring-puckering is small enough to be overcome by the ring-puckering vibration. For the Thietane complex, the analogous barrier is higher than the vibration energy. Therefore, one oxetane and two Thietane complex conformations were observed in the experiment.
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theoretical studies on the oxetane hcl and Thietane hcl complexes
Chemical Physics Letters, 2002Co-Authors: Joanna E. Rode, Jan Cz. DobrowolskiAbstract:Abstract The oxetane⋯HCl and Thietane⋯HCl complexes have recently been studied by rotational spectroscopy in a supersonic jet. In this Letter we report on stability, axial, and equatorial HCl arrangement in the complexes studied by means of MP2 calculations. The shape of the potential functions was studied for the ring-puckering and HCl inversion motions. For the oxetane complex, the barrier of the ring-puckering is small enough to be overcome by the ring-puckering vibration. For the Thietane complex, the analogous barrier is higher than the vibration energy. Therefore, one oxetane and two Thietane complex conformations were observed in the experiment.
Juan E Arguello - One of the best experts on this subject based on the ideXlab platform.
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Photoinduced Electron-Transfer Cycloreversion of Thietanes: The Role of Ion−Molecule Complexes
Organic Letters, 2010Co-Authors: Juan E Arguello, Raúl Pérez-ruiz, Miguel A MirandaAbstract:Cycloreversion (CR) of Thietane radical cations leads to formation of thiobenzophenone and the corresponding alkenes, eventually followed by secondary [4 + 2] cycloaddition. Final product distribution depends on the ability of fragments to escape from ion−molecule complexes (IMCs).
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Photoinduced electron-transfer cycloreversion of Thietanes: the role of ion-molecule complexes.
Organic letters, 2010Co-Authors: Juan E Arguello, Raúl Pérez-ruiz, Miguel A MirandaAbstract:Cycloreversion (CR) of Thietane radical cations leads to formation of thiobenzophenone and the corresponding alkenes, eventually followed by secondary [4 + 2] cycloaddition. Final product distribution depends on the ability of fragments to escape from ion−molecule complexes (IMCs).
