209-22-3Relevant articles and documents
Sulfur monoxide transfer from peri -substituted trisulfide-2-oxides to dienes: Substituent effects, mechanistic studies and application in thiophene synthesis
Grainger, Richard S.,Patel, Bhaven,Kariuki, Benson M.,Male, Louise,Spencer, Neil
supporting information; experimental part, p. 5843 - 5852 (2011/06/22)
Three peri-substituted trisulfide-2-oxides are prepared by treatment of 1,8-naphthalene dithiols with thionyl chloride and pyridine. The 1,2,3-trithiane-2-oxide ring adopts a sofa conformation in the solid state, with a pseudoaxial oxygen and evidence of ring strain (peri-interaction). Heating the trisulfide-2-oxides in the presence of a diene results in formal sulfur monoxide (SO) transfer to form unsaturated cyclic sulfoxides, along with a recyclable 1,8-naphthalene disulfide. The presence of o-methoxy or o-tert-butyl substituents on the naphthalene ring lowers the temperature and increases the rate at which SO transfer occurs. Trapping experiments and kinetic studies are consistent with the generation of triplet SO, followed by in situ trapping by diene. Transfer of SO also occurs upon irradiation at room temperature, but yields of sulfoxide are lower. Dehydration of the sulfoxides under Pummerer conditions gives thiophenes, including the naturally occurring thioperillene. Two dienes form thiophenes directly under the SO transfer conditions. The methodology is applied in a formal synthesis of the antiplatelet medication Plavix.
Generation of ketenes by photolysis of naphtho[1,8-de]-1,3- dichalcogeninylidene 1-oxides
Kobayashi, Kenji,Shinhara, Satoshi,Moriyama, Masaya,Fujii, Takayoshi,Horn, Ernst,Yabe, Akira,Furukawa, Naomichi
, p. 5211 - 5214 (2007/10/03)
The photolysis of naphtho[1,8-de]-1,3-dichalcogeninylidene 1-oxide derivatives (4 and 5) at >290 nm generates ketenes together with naphtho[1,8- cd]-1,2-dichalcogenole, which were confirmed by the trapping experiments and the direct observation using IR spectroscopy. The generation of ketenes from the selenium compounds 5 is more effective than that from the sulfur analogs 4.
Evidence of transannular bonding interaction between two sulfur atoms on photolysis of naphtho[1,8-ef][1,4]dithiepins
Fujii, Takayoshi,Takahashi, Ohgi,Furukawa, Naomichi
, p. 6233 - 6239 (2007/10/03)
Naphtho[1,8-ef][1,4]dithiepins 5 were prepared by the reaction of naphtho[1,8-de]-1,3-dithiins 3 with diethyl diazomalonate in the presence of copper acetylacetonate. The X-ray crystallographic analysis of 2,3-dihydro-2,2-bis(ethoxycarbonyl)-3-phenylnaphtho[1,8-ef][1,4]dithie pin (5a) revealed that the S···S distance is shorter than the sum of their van der Waals radii, indicating that compounds 5 have a strong through-space interaction between the two sulfur atoms. Direct irradiation of 5 with a 500 W high-pressure mercury lamp (313 nm) at room temperature gave the corresponding olefins 6 and naphtho[1,8-cd]-1,2-dithiole (1) quantitatively. The quantum yields of the consumption of 5a and the formation of 6a and 1 were 0.34. The mechanism of this reaction was investigated by examining the effect of sensitization and light intensity. The results indicate that the reaction may proceed by a one-photon process from an excited singlet state. Ab initio calculations were carried out on model compound 7, and it was shown that the excitation to the S1 state causes a bonding interaction between the two sulfur atoms, making the reaction possible.
