1654-52-0Relevant academic research and scientific papers
Synthesis, Characterization, and Flash Vacuum Pyrolysis Studies of anti-(1,6)Azulenophane
Rudolf, Klaus,Robinette, Dan,Koenig, T.
, p. 641 - 647 (1987)
Two short synthetic pathways affording anti-(1,6)azulenophane (3) via fluoride-induced 1,8-eliminations from trimethylsilyl-tetraalkylammonium salts are discussed.The structural assignment of the title compound 3 is based on spectral data.Results from flash vacuum pyrolysis experiments suggest that 3 fractures at 620 deg C to generate the corresponding monomer, 1,6-azulylene (1), a highly reactive polyene.
Synthesis of 1,3,6-Trisubstituted Azulenes
Leino, Teppo O.,Baumann, Marcus,Yli-Kauhaluoma, Jari,Baxendale, Ian R.,Wallén, Erik A. A.
, p. 11513 - 11520 (2015)
We have developed a short, general synthetic route to 1,3,6-trisubstituted azulenes. The key intermediate, 6-methylazulene, was synthesized from readily available and inexpensive starting materials in 63% yield over two steps. The methyl group of 6-methyl
Gold-Catalyzed Direct Alkynylation of Azulenes
Székely, Anna,Péter, áron,Aradi, Klára,Tolnai, Gergely L.,Novák, Zoltán
supporting information, p. 954 - 957 (2017/02/26)
A novel catalytic method for the direct C-H alkynylation of azulenes is developed. The gold catalyzed functionalization of this special carbacycle is achieved with hypervalent iodonium reagent TIPS-EBX under mild reaction conditions. With the aid of the developed procedure, several TIPS alkynylated azulene derivatives were synthesized bearing important functional groups for further functionalization.
Base-promoted Eliminations within Halogenated Propellene Frameworks
Banwell, Martin G.,Halton, Brian,Hambley, Trevor W.,Ireland, Neil K.,Papamihail, Con,et al.
, p. 715 - 724 (2007/10/02)
The reactions of halogenated propellenes with potassium t-butoxide have been investigated.Propelladiene 9,9-dichloro-1,4,5,8-tetrahydro-4a,8a-methanonaphthalene affords 1,6-methanoannulene, 4-methylazulene, and 5H-benzocycloheptene, while the related tetracyclic compound 1,1,8,8-tetrachloro-1a,2,3,6,7,7a-hexahydro-2a,6a-methano-1H-cyclopropanaphthalene reacts to give 12-chlorotricyclo3,5>dodeca-1,3(5),6,8,10-pentaene.Treatment of 8,8-dichloro-2,3,4,7-tetrahydro-3a,7a-methano-1H-indene with the same base produced a mixture of the chlorodiene 8-chloro-2,3-dihydro-3a,7a-methano-1H-indene, azulene, and 4-methylazulene.The structure of the chlorodiene was established by an X-ray crystallographic study of its Diels-Alder adduct with 4-phenyl-4H-1,2,4-triazole-3,5-dione.While reaction of tetracycle 1,1,syn-8-trichloro-1a,2,3,6,7,7a-hexahydro-2a,6a-methano-1H-cyclopropanaphthalene with base failed to produce any characterisable products, under the same conditions epimer 1,1,anti-8-trichloro-1a,2,3,6,7,7a-hexahydro-2a,6a-methano-1H-cyclopropanaphthalene was converted into the cycloproparene tricyclo3,5>dodeca-1,3(5),6,8,10-pentaene.Mechanistic proposals which account for the observed conversions have been advanced and are supported by 13C-labelling studies.The initial steps in most of the reaction pathways of the substrates are probably 1,4-elimination processes involving abstraction of an allylic hydrogen, fragmentation of the strained propellene ?-bond, and ejection of the halogen in an endo-relationship to the abstracted proton.The primary product of these processes, bridgehead dienes such as bicycloundeca-1,3,6(11),8-tetraene, 4,4,12-trichlorotricyclo3,5>dodeca-1(11), 7(12),9-triene and 10-chlorobicyclodeca-1,3,6(10)-triene, then undergo further reaction involving, amongst other things, 1,3-prototropic shifts.Attempts to probe the mode of formation of the C11-4-methylazulene from the C10-precursor 8,8-dichloro-2,3,4,7-tetrahydro-3a,7a-methano-1H-indene have uncovered a novel methylation reaction of azulene by the dimsyl anion.
N.M.R. Studies of Bond Order in Azulene, Biphenylene 1,6-Methanoannulene
Collins, Michael J.,Sternhell, Sever,Tansey, Charles W.
, p. 1541 - 1546 (2007/10/02)
The 4J coupling constants of methyl-substituted derivatives, probes of bond order, have been used to examine the ground-state ?-electron distributions in azulene (1), biphenylene (2) and 1,6-methanoannulene (3).The experimental data obtained are in good agreement with theoretical predictions for biphenylene (2) and provide some evidence for ?-electron disproportionation towards the five-membered ring in azulane (1).The bond orders in 1,6-methanoannulene (3) obtained in this work are at variance with those predicted on the grounds of bond lenghts.
A Short New Azulene Synthesis
Scott, Lawrence T.,Minton, Mark A.,Kirms, Mark A.
, p. 6311 - 6314 (2007/10/02)
A short new azulene synthesis requiring no dehydrogenation step, has been developed (Scheme 1).Intramolecular carbene addition creates the bicyclic ring system of azulene with a high degree of unsaturation and versatile functionality in a single step from a simple benzene derivative.The synthesis is particularly amenable to preparation of specific 13C- and 2H-labeled azulenes.
