Generation and trapping of a highly strained bicyclic alkyne: Tricyclo[,7)]dodeca-2,4,6-trien-9-yne

Tumer, F
Taskesenligil, Y
Balcı, Metin
High-temperature bromination of 10-bromotricyclo[,7)]dodeca-2,4,6,9-tetraene (8) resulted mainly in the formation of two isomeric tribromides (16 and 17) whose dehydrobromination with DBU afforded the corresponding 9,10-dibromotricyclo [,7)] dodeca-2,4,6,9-tetraene (14). Treatment of 14 with tert-butyllithium in THF at -78 degreesC produces the strained bicyclic alkyne (10) which is trapped by 1,3-diphenylisobenzofuran to give two isomeric cycloadducts 12a and 12b. The adducts 12a and 12b were found to readily rearrange to the isomeric ketones 19a and 19b upon chromatography. Upon treatment with potassium tert-butoxide, the adducts 12a and 12b undergo base-catalyzed double bond isomerization to give four products 20-23. Furthermore, reaction of 14 with one and two mole of potassium tert-butoxide has been studied and the mechanism of the product formation is discussed with regard to either an allene or alkyne as a possible intermediate.


Synthesis and electrochromic properties of conducting copolymers of dioxocino- and dithiocino-quinoxalines with bithiophene
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Two new monomers, 2-benzyl-5,12-dihydro-2H-pyrrolo[3',4':2,3][1,4]dioxocino[6,7-b]quinoxaline (DPOQ) and 5,12-dihydrothieno[3',4':2,3][1,4]dithiocino[6,7-b]quinoxaline (DTTQ), were synthesized. The chemical structures of the monomers were characterized by nuclear magnetic resonance (H-1 NMR), Fourier transform infrared (FTIR) and mass spectra. Copolymer of DPOQ with bithiophene (BT) was synthesized via potentiostatic electrochemical polymerization in acetonitrile-tetrabutylammonium tetrafluoroborate solvent...
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Ten different N-propargyl pyrrole derivatives having various substituents at the C-2 position were synthesized. These derivatives were converted into indolizine derivatives by the [2+2] cycloaddition reaction of pyrrole N-allene, forming in situ, by heating in PrOH in basic medium. The structures were characterized by NMR and X-ray crystallography. The N-propargylated derivatives smoothly underwent intermolecular cyclizations to produce indolizine derivatives in good yields. We proposed a radical mechanism ...
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Copolymers containing oligo(phenylene vinylene) (2.5), fluorene, and 4,4-dihexyldithienosilole (DTS) units were synthesized and characterized. The pi-conjugated monomers were joined with the palladium(0)-catalyzed Suzuki-Miyaura coupling reaction, thus forming either biphenyl- or phenyl-thiophene linkages. These polymers were photoluminescent, with the fluorescent quantum efficiency between 54 and 63% and with),lambda(max) for fluorescence at similar to 448 nm in tetrahydrofuran. The presence of 5% DTS in t...
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Synthesis and mesophase properties of block and random co-polymers of electroactive and liquid crystalline monomers
Yilmaz, F; Kasapoglu, F; Hepuzer, Y; Yagci, Y; Toppare, Levent Kamil; Fernandes, EG; Galli, G (Informa UK Limited, 2005-01-01)
Homo-polymers and random co-polymers of electroactive and liquid crystalline monomers, namely 3-thienylmethyl methacrylate (MTM) and 6-(4-cyanobiphenyl-4'-oxy)hexyl acrylate (LC6), were prepared by conventional free radical polymerization. Block co-polymers of MTM and LC6 were also synthesized by using the 1,1-diphenylethene (DPE) method. The obtained random and block co-polymers exhibited liquid crystal behavior depending on the content of the LC6 units. It was found that microphase separation of the polym...
Citation Formats
F. Tumer, Y. Taskesenligil, and M. Balcı, “Generation and trapping of a highly strained bicyclic alkyne: Tricyclo[,7)]dodeca-2,4,6-trien-9-yne,” JOURNAL OF ORGANIC CHEMISTRY, pp. 3806–3810, 2001, Accessed: 00, 2020. [Online]. Available: