High temperature bromination. Part 12: Bromination of 7-oxabenzonorbornadiene: Synthesis of 2,3-dibromo-7-oxabenzonorbornadiene

Altundas, A
Dastan, A
McKee, MM
Balcı, Metin
The electrophilic addition of bromine to 7-oxabenzonorbornadiene (8) at 0 degrees C led in high yield to the formation of dibromoaldehyde 10. However, high-temperature bromination of 8 in carbontetrachloride at 77 degrees C gave non-rearranged products 17 and 18. From the elimination of non-rearranged products, 2-bromo-7-oxabenzonorbornadiene (12) was obtained. Similarly, bromination of monobromide 12 at 77 degrees C yielded the non-rearranged tribromides 19 and 20 while bromination of 12 at 0 degrees C gave the rearranged product 11. The dehydrobromination of tribromides (19, 20) provided the 2,3-dibromo-7-oxabenzonorbornadiene (21), which is a synthon for the trimerization, in high yield


High temperature bromination. Part 18: Bromination of benzonorbornadiene derivatives: Polybrominated benzonorbornenes and benzonorbornadienes
Dastan, A; Balcı, Metin (Elsevier BV, 2005-06-06)
The low and high temperature bromination reactions of bromobenzonorbornadiene derivatives were studied and the possible role of a neighboring group in rearrangements was investigated. New polybrominated benzonorbornadiene and benzonorbornene derivatives were synthesized. All compounds were characterized property Using NMR spectroscopy.
High temperature bromination. Part 22: Bromination of 1a,2,7,7a-tetrahydro-1H-cyclopropa[b] naphthalene
Demirci-Gueltekin, Demet; Guenbas, Duygu D.; TAŞKESENLİGİL, Yavuz; Balcı, Metin (Elsevier BV, 2007-08-20)
The high-temperature bromination of 1a,2,7,7a-tetrahydro-1H-cyclopropa[b] naphthalene and its carboethoxy derivative was studied. Reaction of the title compound with 1 mol of bromine in refluxing carbon tetrachloride resulted in the formation of ring-opening products. In the case of the carboethoxy derivative,bromination took place both regio- and stereospecifically at the benzylic positions,the cyclopropane ring did not undergo bond cleavage. A mechanism for the formation of the products and their dehydrob...
Distyryl-boradiazaindacenes: facile synthesis of novel near IR emitting fluorophores
Dost, Zeynep; Atilgan, Serdar; Akkaya, Engin U. (Elsevier BV, 2006-09-04)
Boradiazaindacenes with methyl substituents at 3 and 5 positions were for the first time shown to undergo efficient double condensation reactions with an aromatic aldehyde yielding a series of extended conjugation dyes. These new fluorophores have absorption maxima in the range of 650-660 nm. The dyes reported here have large quantum yields with 20 nm Stokes' shifted emission peaks. The straightforward synthesis of such red shifted BODIPY derivatives is important in relation to the synthesis of novel and us...
Low and high temperature bromination of exocyclic dienes: high temperature bromination. Part 16
Horasan, N; Kara, Y; Azizoglu, A; Balcı, Metin (Elsevier BV, 2003-05-19)
The electrophilic addition of bromine to an exocyclic diene, 5,6-dimethylenebicyclo[2.2.1]hept-2-ene, in CCl4 at 0degreesC led to the formation of non-rearranged (73%) and rearranged products (27%). However, high temperature bromination of the exocyclic diene at 77degreesC suppressed the formation of the rearranged products. Similarly, bromination of 9,10-dimethylenetricyclo[]undeca-2,4,6-triene at -10degreesC gave only the exo-1,2-addition product. Bromination at +5degreesC resulted in the form...
Infrared fluorescence sensing of submicromolar calcium: pushing the limits of photoinduced electron transfer
Ozmen, B; Akkaya, EU (Elsevier BV, 2000-11-18)
A heptamethine cyanine-BAPTA conjugate was synthesized which signals calcium binding by an almost 4-fold increase in the emission intensity at the emission maximum of 782 nm. This significant enhancement factor opens new possibilities for the development of IR fluorescent chemosensors excitable with an inexpensive 780 nm laser diode and detectable with highly sensitive avalanche diodes.
Citation Formats
A. Altundas, A. Dastan, M. McKee, and M. Balcı, “High temperature bromination. Part 12: Bromination of 7-oxabenzonorbornadiene: Synthesis of 2,3-dibromo-7-oxabenzonorbornadiene,” TETRAHEDRON, pp. 6115–6120, 2000, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57470.