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Thiophene compounds yield, oligothiophenes

Naarmann et al. used exactly the same reactions to synthesize the whole series of a-oligothiophenes up to H—Tg-H 6. No yields are given, but the authors paid very much attention to the purification procedure and the physical constants of the various thiophene oligomers [12]. The use of iodo compounds proved to be even more effective, since H—T2—H 2 was obtained by the nickel-catalyzed coupling [Ni(dppe)Cl2] of I—Tj—H 8 and its Grignard derivative in 90% yield [78]. [Pg.101]

Nakayama et at. used thienyl-substituted 1,4-dithiins which are obtained from easily accessible diketosulfides for the preparation of a-oligothiophenes and isomers up to the heptamer [37b, 120]. The dithienyldiketosulfides 91-93 are prepared by the reaction of chloroaeetyl-substituted (oligo)thiophenes and sodium sulfide in almost quantitative yield and are further cyclized to the corresponding 1,4-dithiins 94-96 with L.R. in 60% yield. The extrusion of sulfur from the dithiin moiety via ylide intermediates is achieved by refluxing the dithiin in o-dichlorobenzene and results in a mixture of two possible isomers [Eq. (45)]. In the case of 2,6-di-(2 thienyl)-1,4-dithiin 94, a ratio of 13 1 of H-T3-H 3 and the 2,3 4, 2"-isomer 97 in 85% yield is obtained. The separation of the compounds by recrystallization turns out well since the a,/ -connected terthiophene is better soluble in hexane. Oxidation of the dithiin with nz-chloroperoxybenzoic add and extrusion of SO from the resulting sulfoxide in the presence of DMSO afford a mixture of H-T3-H 3 and the isomer 97 in a ratio of 22 1 and in a total yield of 90% [120]. [Pg.110]


See other pages where Thiophene compounds yield, oligothiophenes is mentioned: [Pg.276]    [Pg.956]    [Pg.28]    [Pg.236]    [Pg.237]    [Pg.268]    [Pg.90]    [Pg.94]    [Pg.98]    [Pg.103]    [Pg.143]    [Pg.154]    [Pg.156]    [Pg.161]    [Pg.166]    [Pg.168]    [Pg.173]    [Pg.31]    [Pg.147]    [Pg.133]   
See also in sourсe #XX -- [ Pg.117 ]

See also in sourсe #XX -- [ Pg.117 ]

See also in sourсe #XX -- [ Pg.117 ]




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