30456-90-7Relevant academic research and scientific papers
TROPOTHIONE. SYNTHESIS, SPECTRA AND CHEMICAL REACTIONS
Machiguchi, Takahisa,Otani, Hiroyuki,Ishii, Yukiko,Hasegawa, Toshio
, p. 203 - 206 (1987)
Tropothione has been effectively synthesized as unstable red crystals and fully characterized by various spectroscopies as well as pKa and dipole moment measurements together with chemical characterization reactions.The properties of tropothione was revealed to differ considerably from those of tropone.
Synthesis and Isolation of Tropothione: A Comparative Study of Spectral Property with Tropone
Machiguchi, Takahisa
, p. 1133 - 1142 (1995)
The synthesis, isolation, and spectral characterization of tropothione (1), the sulfur analogue of tropone (2), are described with comparison of those for 2.Direct sulfurization of 2 with tetraphosphorous decasulfide using triethylamine as a catalyst yields the titled compound 1 in high yield.Although 1 is thermally unstable material 1/2(crystalline state, 0 deg C) 56 min>, dilute solutions are found to be sufficiently stable enough for measuring spectral data 1/2(0.01 mol/L, 25 deg C) 10.4 days>.The compound 1 is isolated as a labile material of deep red crystals with the melting range of 20-21 deg C.IR spectrum of 1 exhibits a very strong band of the νC=S stretching vibration at 1087 cm-1 in CCl4.Raman spectrum supports the assignment.UV-visible spectra in six solvents show three transitions at around 225 (log ε ca. 4), 253 (ca. 4), and 380 nm (ca. 4.2), while 1 exhibits an additional weak absorption of n-?* transitions at 610 nm (log ε 1.62). 1H NMR of 1 shows wide signals of symmetrical AA'BB'XX' pattern comprising with a large downfield part of α-protons in the ring due to the magnetic anisotropy of the C=S group greater than that of C=O one in 2. 13C NMR of 1 displays three doublet signals (δ 131.48, 138.36, and 153.80) accompanying with the singlet one at δ 213.83 (C=S). 33S NMR of 1 exhibits δ-287 as the first measurement for thiocarbonyl compounds.These physical properties of 1 are in sharp contrast to those of 2.
Inverting the reactivity of troponoid systems in enantioselective higher-order cycloaddition
Frankowski, Sebastian,Skrzyńska, Anna,Albrecht, ?ukasz
supporting information, p. 11675 - 11678 (2019/10/02)
By the replacement of the oxygen with the sulfur atom in tropone, a novel reactivity pattern of troponoid systems in enantioselective transformation was achieved. It utilizes tropothione as an 8π-component in the [8+2]-cycloaddition involving α,β-unsaturated aldehydes. The stereochemistry of the process is governed through the aminocatalytic LUMO-activation of the carbonyl reactant. It is in marked contrast to recently developed aminocatalytic higher-order cycloadditions proceeding via HOMO-activation strategies.
ZUR ZUORDNUNG DER 13C-NMR-SPEKTREN DES TROPONS UND DES THIOTROPONS
Poleschner, Helmut,Radeglia, Reiner
, p. 193 - 200 (2007/10/02)
The 13C-NMR-spectrum of tropone is assigned precisely by the combined application of various methods (shift reagent technique, off-resonance at different decoupling frequencies for 1H-13C shift correlation).The results confirm previously obtained data.The assignment of the thiotropone 13C-NMR chemical shifts is brought about by a correlation between the respective thiotropone and tropone shift values at the same positions.This means that previously published data should be revised.The research deals with the shift effects (1.) during the change from carbonyl to the thiocarbonyl compound in the series tropone/thiotropone as well as the iso ? electronic sulfur heterocycles thiopyrane-2-one/thiopyrane-2-thione, 1,2-dithiole-3-one/1,2-dithiole-3-thione and 1,3-dithiole-2-one/1,3-dithiole-2-thione and (2.) in the series tropone, cyclohepta-2,4-dienone, cyclohepta-2,6-dienone, cyclohept-2-enone and cycloheptanone.In this series a transition from a shift sequence typical of α,β-unsaturated carbonyl compounds to a tropone like shift sequence can be observed.
