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4 Polish Journal of Chemistry

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New Thiocarbonyl Ylides Derived from 3,3-Dichloro-2,2,4,4-tetramethylcyclobutanethione; Generation and Reactions

Woźnicka M., Rutkowska M., Mlostoń G., Majchrzak A., Heimgartner H.

Polish Journal of Chemistry

2006

Vol. 80, nr 10

1683-1693

Chemoselectivity of the [2+3]-Cycloaddition of Thiocarbonyl Ylides with 5-Benzylidene-3-phenylrhodanine

Seyfried M., Linden A., Mlostoń G., Heimgartner H.

Polish Journal of Chemistry

2006

Vol. 80, nr 8

1363-1376

Reactions of three different thiocarbonyl S-methylides, generated from thiobenzophenone (2), 2,2,4,4-tetramethyl-3-thioxocyclobutanone (3), and adamantanethione (8), respectively, and diazomethane, with 5-benzylidene-3-phenylrhodanine (12) were carried out. The aromatic thiocarbonyl ylide 1a adds chemoselectively to the C,C-double bond, but the spirocyclic 1,3-dithiolane 18, i.e. the [2+3]-cycloadduct with the C=S group of 12,was also formed as a minor product. In the cases of the aliphatic thiocarbonyl ylides 6 and 20, the [2+3]-cycloaddition occurred at the exocyclic C,C-double bond exclusively to give the spirocyclic tetrahydrothiophene derivatives 23 and 21, respectively. Asmooth acid-catalyzed decomposition of 18 yielded the 2-diphenylmethylidene derivative 19. The formation of product 24, which was obtained in the reaction of the sterically congested ylide 6 with 12, is explained by a 1,4-H-shift in an intermediate zwitterionic adduct. The structures of the tetrahydrothiophenes 17, 21 and 23, as well as that of 24, were established by X-ray crystallography.

Synthesis and Structure of Spirocyclic Tetrahydrothiophene Derivatives Bearing a 'Cage' Residue

Romański J., Mlostoń G., Linden A., Heimgartner H.

Polish Journal of Chemistry

2005

Vol. 79 / nr 6

973-979

Trapping of the thiocarbonyl S-methanide 4 with tetracyanoethene and N-methylmaleimide led to the [3+2]-cycloadducts 11 and 12, respectively. The structures of these cycloadducts were established by X-ray crystallography. The 1,3-dipole 4 has been generated by thermal decomposition of the corresponding 2,5-dihydro-1,3,4-thiadiazole 2, which was prepared by the 1,3-dipolar cycloaddition of diazomethane with thioketone 1.

Polycyclic [2+3]-Cycloadducts from the Thermal Decomposition of Bis(2,5-dihydro-1,3,4-thiadiazoles) in the Presence of N-Methylmaleimide

Mlostoń G., Celeda M., Linden A., Heimgartner H.

Polish Journal of Chemistry

2004

Vol.78 /nr 11-12

2089-2099