Endo- and Exo-Configured Cyclopropylidenes Incorporated into the Norbornadiene Skeleton: Generation, Rearrangement to Allenes, and the Effect of Remote Substituents on Carbene Stability

Kilbas, Benan
Azizoglu, Akin
Balcı, Metin
For the synthesis of endo-configured cyclopropylidenes annelated to benzonorbornadiene, first the exo-bridge hydrogen in benzonorbornadiene was blocked with ethyl, bromine, and methoxy groups. All efforts to add dichloro-, dibromo-, or fluorobromocarbenes to ethylbenzonorbornadiene failed. However, addition of fluorobromocarbene to bromo- or methoxybenzonorbornadiene gave the corresponding cyclopropane derivatives bearing two halogen atoms, which were submitted to the Doering-Moore-Skattebol reaction. The formed allene intermediates were trapped with furan. The reactivity of the double bonds in substituted benzonorbornadienes was analyzed by determination of the pyramidalization angles. Furthermore, the relative energies of various carbenes and their rearrangement to allene were studied at B3LYP/6-31G(d) level.


Tanyeli, Cihangir (Informa UK Limited, 1989-01-01)
Some phenolic biphenyl compounds have been synthesised via the annulation reactions of 4-methoxy-2- pyrone with various active methyl compounds.
Naphthazarin-Polycyclic Conjugated Hydrocarbons and Iptycenes
Dengiz, Çağatay; GUTIERREZ, Gregory D.; SWAGER, Timothy M. (American Chemical Society (ACS), 2017-07-21)
The synthesis of a set of naphthazarin-containing polycyclic conjugated hydrocarbons is described herein. Sequential Diels-Alder reactions on a tautomerized naphthazarin core were employed to access the final conjugated systems. Complete conjugation across the backbone can be achieved through complexation with BF2, as observed by (HNMR)-H-1 analysis and UV/vis spectroscopy. Precise synthetic control over the degree of oxidation of naphthazarin quinone Diels-Alder adduct 10 is additionally demonstrated and e...
Generation of acyl anion equivalents from acylphosphonates via phosphonate-phosphate rearrangement: A highly practical method for cross-benzoin reaction
Demir, Ayhan Sıtkı; Reis, O; Igdir, AC; Esiringu, I; Eymur, S (American Chemical Society (ACS), 2005-12-09)
Acylphosphonates are potent acyl anion precursors that generate acyl anion equivalents under the promotion of cyanide anion via phosphonate-phosphate rearrangement. These anions readily react with aldehydes to provide cross-benzoin products. In this way it is possible to synthesize a variety of aromatic-aromatic, aromatic-aliphatic, and aliphatic-aromatic benzoins. Moreover the reaction of benzoylphosphonate with potent electrophile 2,2,2-trifluoroacetophenone provided the corresponding aldehyde-ketone coup...
Manganese(iii)acetate-based free-radical additions of -dicarbonyl compounds to bicyclic systems
Fedalla, Mohammad Ali; Balcı, Metin; Department of Chemistry (2007)
Additions of carbon-centered radicals to alkenes are useful method for cyclic compounds formation. Manganese(III)-based oxidative free-radical cyclizations, where the radicals are generated and terminated oxidatively, are established as efficient methods for the construction of cyclic molecule. Treatment of a mixture of dimedone, Mn(OAc)3, and Cu(OAc)2 in glacial acetic acid with homobenzonorbornadiene (80) (4h at 50 C) gave furan derivative (107), dihydrofuran adduct (108), in addition to rearranged produc...
Fam-zinc catalyzed asymmetric 1,3-dipolar cycloaddition reactions of azomethine ylides and
Koyuncu, Hasan; Doğan, Özdemir; Department of Chemistry (2007)
In the first part of this study, four new chiral ligands (FAM) were synthesized and used in catalytic amounts in asymmetric 1,3-dipolar cycloaddition reactions of azomethine ylides. This method leads to the synthesis of chiral pyrrolidines, which are found in the structure of many biologically active natural compounds and drugs. It was found that using 10 mol% of one of these chiral ligands with different dipolarophiles (dimethyl maleate, dimethyl fumarate, methyl acrylate, tert-butyl acrylate, and Nmethylm...
Citation Formats
B. Kilbas, A. Azizoglu, and M. Balcı, “Endo- and Exo-Configured Cyclopropylidenes Incorporated into the Norbornadiene Skeleton: Generation, Rearrangement to Allenes, and the Effect of Remote Substituents on Carbene Stability,” JOURNAL OF ORGANIC CHEMISTRY, pp. 7075–7083, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57489.