258-47-9

Upstream product

• 76240-62-5 C₂₆H₁₆N₂O₂ 
• 13214-70-5 2,3-dibromonaphthalene 
• 14734-19-1 anti-2,3,2',3'-Tetrahydro-2,2',3,3'-bis-(naphthochinon-(1,4)-ylen) 
• 57787-00-5 1,2-dibromo-1,2-dihydrocyclobutanaphthalene 
• 91-13-4 α,α'-dibromo-o-xylene 
• 30013-93-5 1,2,3,4,7,8,9,10-Octahydro-dibenzobiphenylen 
• 259-79-0 bisbenzocyclobutene 
• 5959-52-4 2-Amino-3-naphthoic acid 
• 30013-90-2 2,6-Bis-(3-carboxypropyl)-biphenylen 
• 30013-91-3 3,4,9,10-Tetrahydrodibenzobiphenylen-1(2H),7(8H)-dion 
• 102317-09-9 3,3'-dinitro-5,6,7,8,5',6',7',8'-octahydro-[2,2']binaphthyl 
• 109931-75-1 3,3'-dinitro-[2,2']binaphthyl 
• 13115-28-1 3-nitronaphthalen-2-amine 
• 198406-46-1 3,3’-dibromo-2,2’-binaphthalene 

Relevant academic research and scientific papers

Synthesis of biphenylenes and tetraphenylenes using copper-catalyzed coupling of arylzinc intermediates

Biphenylene and some of its 2,3,6,7- and 1,8-substituted derivatives were synthesized using the CuCl2-mediated intramolecular coupling of an organozinc species prepared from 2,2′-dilithiobiaryls with one or two molar equiv. of ZnCl2 or ZnBr2 in THF. Although most of the reactions of 2,2′-dilithiobiaryls with CuCl2 in THF in the absence of ZnCl2 or ZnBr2 led to biphenylenes as a major product, similar reactions of the organozinc species with CuCl2 in THF produced biphenylenes in much better yields, due to smooth transmetallation and reductive elimination reactions. In particular, the copper-mediated cyclization of benzannelated organozinc intermediates, prepared from equimolar proportions of 2,2′-dilithiobiaryls with ZnCl2, proceeded smoothly and selectively to afford the desired biphenylenes in 46-81% yield except for the reaction of the zinc intermediate derived from 4,4′,5,5′-tetramethoxy-2,2′-dilithiobiphenyl with ZnCl2 (1.0 molar equiv.). The reaction of the tetramethoxy-substituted organozinc species with CuCl2 produced 2,3,6,7,10,11,14,15-octamethoxytetraphenylene as a major product in 67% yield.

Novel synthesis of biphenylene and its derivatives using intramolecular coupling of zincacyclopentadienes

Biphenylene and its derivatives were synthesized using the intramolecular coupling of benzoannelated zincacyclopentadiene intermediates prepared from 2,2'-dilithiobiaryls with ZnCl2. The reaction proceeded smoothly and selectively to give the desired biphenylenes in moderate to good yields.

The EPR Spectrum of the Dibenzobiphenylene Radical Anion and Cation: the Pairing Principle and the Mills-Nixon Effect

The EPR/ENDOR spectra of the radical ions of dibenzobiphenylene provide an exception to the rule (the pairing principle) that these spectra should be similar in the radical cation and anion of planar alternant hydrocarbons.It is suggested that this breakdown of the pairing principle can be understood in terms of the Finnegan-Streitwieser model of the Mills-Nixon effect, which, by inducing charge separation and changes in bond lengths, can exchange the ordering of the energy levels of adjacent orbitals.

Benzocyclobutenes. Part 4. Synthesis of Benzocyclobutene-1,2-diones by Pyrolytic Methods

Oxidation of the cyclic hydrazides prepared from phthalic anhydrides in the presence of anthracene gives the corresponding Diels-Alder adducts which, on flash vacuum pyrolysis, give benzocyclobutene-1,2-dione (BBD) and its 4-chloro, 3,6- and 4,5-dichloro, 4,5-dibromo, and 4,5-dimethyl derivatives in 75-98percent yield.Cyclobuta- and cyclobuta-naphthalene-1,2-dione as well as cyclobuta- and cyclobuta-pyridine-1,2-dione have been prepared similarly; the last three of these diones are very unstable.Cyclobutanaphthalene-1,2-dione has also been made by pyrolysis of benzindene-1,2,3-trione.Attempts to make thiophen and furan analogues of BBD from appropriate anthracene adducts failed as did attempts to make tetrachloro- and tetrabromo-derivatives of BBD by the pyrolysis of tetrahalogenophthalimidosulphoximides.