205-82-3Relevant articles and documents
Synthesis, molecular structure, and chemical reactivity of azuleno[1,2-a]acenaphthylene
Mouri, Masaru,Kuroda, Shigeyasu,Oda, Mitsunori,Miyatake, Ryuta,Kyogoku, Mayumi
, p. 801 - 811 (2003)
The azuleno[1,2-a]acenaphthylene (1a) was prepared from 1-pyrrolidinylacenaphthylene (5) and 2H-cyclohepta[b]furan-2-one (6) by the method of the Takase-Yasunami azulene synthesis. Its 1H and 13C NMR spectra indicate that 1a comprises azulene and naphthalene rather than acenaphtylene and heptafulvene in accordance with speculation drawn from a previous study of the DEPE calculations. The solid-state structure of 1a was elucidated by X-ray crystallographical analysis, indicating that 1a is nearly planar and exhibits little bond alternation as seen in the optimized structure at the MB3LYP/6-311G* level of theory. All bond lengths observed by the X-ray analysis are in good agreement within 0.024? with those calculated. Under pyrolytic conditions 1a underwent azulene-naphthalene rearrangement to give 9 and 10. The electrophilic substitution of 1a was observed at the 7-position and the second reaction at the 3-position. The cycloaddition reaction of 1a with dimethyl acetylenedicarboxylate (DMAD) yielded the 1:1 cycloadduct with a heptalene skeleton 16a and the 1:2 cycloadduct 19, along with the substitution product 17. The X-ray structural analysis of the cycloadducts 16a and 19 is also described.
High temperature gas phase syntheses of C20H12 cyclopenta-fused polycyclic aromatic hydrocarbons: Benz[l]acephenanthrylene and benz[j]acephenanthrylene and their selective rearrangement to benzo[j]fluoranthene
Sarobe, Martin,Jenneskens, Leonardus W.,Wesseling, Jolanda,Wiersum, Ulfert E.
, p. 703 - 708 (1997)
The novel C20H12 cyclopenta-fused polycyclic aromatic hydrocarbon benz[l]acephenanthrylene (2) and its isomer benz[j]acephenanthrylene (3) have been obtained by flash vacuum thermolysis of 2-(1-chloroethenyl)benzo[c]phenanthrene (6) and 6-(1-chloroethenyl)chrysene (7), respectively. At T ≥ 900°C 2 and T ≥ 1000°C 3 rearrange selectively to the abundant combustion effluent benzo[j]-fluoranthene (1). No evidence for the presence of the related rearrangement products benz[l]aceanthrylene (12) and benz[j]aceanthrylene (13), respectively, is found. Semi-empirical AM1 calculations provide a rationalization for these observations; the conversion of 2 and 3 into 1, instead of 12 and 13, respectively, via consecutive ring-contraction-ring-expansion processes and vice versa is favoured.
Acid-Catalyzed Cyclization of 3,3',4,4'-Tetrahydro-1,1'-binaphthyl and Single-Crystal X-ray Structure Determination of a Polycyclic Stable Ozonide
Dobbs, Thomas K.,Taylor, Arnold R.,Barnes, Julie A.,Iscimenler, Belma D.,Holt, Elizabeth M.,Eisenbraun, Edmund J.
, p. 1030 - 1033 (1984)
Amberlyst-15 (A-15) catalyzed cyclization of 3,3',4,4'-tetrahydro-1,1'-binaphthyl (1) in refluxing toluene during 12h provided , as the major product , (+/-)-1,2,3,6b,7,8-hexahydrobenzofluoranthene (2a).Ozonization of 2a gave a stable ozonide (3), mp 159-161 deg C.The structure of this ozonide was established by single-crystal X-ray analysis: monoclinic unit cell P21/c, a= 10.616(1) Angstoem, b= 9.607(3) Angstroem, c= 15.052(4) Angstroem, β= 105.06(2) deg, Dcalcd 1.372 g cm-1, Z= 4, final agreement factor 6.3percent.Prolonged treatment (12-100 h) of 1 or 2a with A-15 in refluxing toluene yielded a mixture of three1,2,3,6b,7,8,12b,12c-octahydrobenzofluoranthenes ( 4a, 4b, 4c) and 1,2,3,12c-tetrahydrobenzofluoranthene (5).Hydrocarbon 2a was readily dehydrogenated in the presence of hot Pd/C to benzofluoranthene (6).
Three-Step Synthesis of Fluoranthenes through Pd-Catalyzed Inter- and Intramolecular C-H Arylation
Yamaguchi, Miyuki,Higuchi, Mayu,Tazawa, Kanae,Manabe, Kei
, p. 3967 - 3974 (2016/05/24)
A three-step synthetic method for the preparation of fluoranthenes, involving Miura's intermolecular C-H arylation, nonaflation, and intramolecular C-H arylation, has been developed. Various 1-naphthols and haloarenes were successfully used as substrates. Reaction conditions that afford high site selectivity have been developed for the intramolecular C-H arylation step.
Use of external radical sources in flash vacuum pyrolysis to facilitate cyclodehydrogenation reactions in polycyclic aromatic hydrocarbons
Amick, Aaron W.,Martin, Sara E.
, p. 1338 - 1343 (2014/11/08)
A new process to facilitate the cyclodehydrogenation of polycyclic aromatic hydrocarbons (PAHs) in flash vacuum pyrolysis (FVP) using an external radical source is described. Using hexanes as an external radical source the conversion of various PAHs to their cyclodehydrogenated products is vastly increased. Various other volatile organic compounds were also examined to determine their ability to act as external radical sources in FVP.
Total synthesis of the natural product benzo[j]fluoranthene-4,9-diol: An approach to the synthesis of oxygenated benzo[j]fluoranthenes
Lahore, Santosh,Narkhede, Umesh,Merlini, Lucio,Dallavalle, Sabrina
, p. 10860 - 10866 (2013/11/19)
A synthetic sequence to the benzo[j]fluoranthene nucleus is described. Crucial steps of the procedure include a Suzuki coupling between appropriately substituted 2-bromo-acenaphthylene-1-carbaldehydes and 2-formylbenzeneboronates followed by McMurry ring closure. The synthesis represents a new approach to the benzo[j]fluoranthene ring system and specifically provides a method for the rapid preparation of differently substituted derivatives. Following this strategy, the first total synthesis of the recently isolated natural product benzo[j]fluoranthene-4,9-diol was carried out.
Microwave flash pyrolysis
Hee, Yeon Cho,Ajaz, Aida,Himali, Dibya,Waske, Prashant A.,Johnson, Richard P.
supporting information; experimental part, p. 4137 - 4142 (2009/09/25)
(Chemical Equation Presented) In a microwave reactor, graphite heats rapidly to high surface temperatures; applications of graphite thermal "sensitization" have been described previously. We report here that microwave thermal sensitization with graphite, carbon nanotubes, or silicon carbide can be used to carry out reactions more typically accomplished by flash vacuum pyrolysis (FVP) and which usually require temperatures much higher than the nominal limit of a microwave reactor. The graphite-sensitized microwave reaction of azulene in the solid phase at temperatures of 100 to 300°C affords rapid rearrangement to naphthalene, a reaction typically observed by FVP at 700-900°C. Multiwall carbon nanotubes give similar results when used as a thermal sensitizer. Other graphite-sensitized reactions that we have observed include the following: conversion of 2-ethynylbiphenyl to phenanthrene, fragmentation of phthalic anhydride to benzyne, cleavage of iodobenzene to phenyl radical, aryl-aryl bond cleavage, and a variety of cycloaromatizations. An advantage is seen for less volatile substrates. Rearrangement of azulene and generation of benzyne from phthalic anhydride have also been observed on powdered silicon carbide. Because of the high temperature, rapid heating, and frequent ejection of material from the irradiation zone, we refer to this general method as microwave flash pyrolysis (MFP).
Emission factors and importance of PCDD/Fs, PCBs, PCNs, PAHs and PM 10 from the domestic burning of coal and wood in the U.K.
Lee, Robert G. M.,Coleman, Peter,Jones, Joanne L.,Jones, Kevin C.,Lohmann, Rainer
, p. 1436 - 1447 (2007/10/03)
This paper presents emission factors (EFs) derived for a range of persistent organic pollutants (POPs) when coal and wood were subject to controlled burning experiments, designed to simulate domestic burning for space heating. A wide range of POPs were emitted, with emissions from coal being higher than those from wood. Highest EFs were obtained for particulate matter, PM10, (～ 10 g/kg fuel) and polycyclic aromatic hydrocarbons (～ 100 mg/ kg fuel for ΣPAHs). For chlorinated compounds, EFs were highest for polychlorinated biphenyls (PCBs), with polychlorinated naphthalenes (PCNs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) being less abundant. EFs were on the order of 1000 ng/kg fuel for ΣPCBs, 100s ng/ kg fuel for ΣPCNs and 100 ng/kg fuel for ΣPCDD/Fs. The study confirmed that mono- to trichlorinated dibenzofurans, Cl1,2,3DFs, were strong indicators of low temperature combustion processes, such as the domestic burning of coal and wood. It is concluded that numerous PCB and PCN congeners are routinely formed during the combustion of solid fuels. However, their combined emissions from the domestic burning of coal and wood would contribute only a few percent to annual U.K. emission estimates. Emissions of PAHs and PM 10 were major contributors to U.K. national emission inventories. Major emissions were found from the domestic burning for Cl1,2,3DFs, while the contribution of PCDD/F-ΣTEQ to total U.K. emissions was minor.
Efficient routes to acenaphthylene-fused polycyclic arenes/heteroarenes and heterocyclic fluoranthene analogues
Panda, Kausik,Venkatesh, Chelvam,Ila, Hiriyakkanavar,Junjappa, Hiriyakkanavar
, p. 2045 - 2055 (2007/10/03)
The acenaphthenone-derived a-oxoketene dithioacetal 2 has been subjected to various [3 + 3] aromatic and heteroaromatic annulation and other heterocyclization reactions previously developed in our laboratory, providing short and efficient routes to a diverse range of known and unknown acenaphtho-annulated linear and angular PAHs, heteroaromatics and five-membered heterocycles in good yields. Thus, benzo- and naphthoannulation of 2 with various allyl and benzyl Grignard reagents afforded substituted fluoranthenes 4a-c and benzo[k]fluoranthene 8, respectively, in good yields. Similarly, the parent benzo[j]fluoranthene 15a and its substituted derivative 16b have been synthesized by base-induced conjugate 1,4-addition of arylacetonitriles to 2, followed by acid-induced cyclization of the conjugate adducts 12a-b to give 13a-b and subsequent further transformations. The adducts obtained by 1,4-addition of anions derived from acetophenone and acenaphthenone were subjected to heterocyclization in the presence of ammonium acetate to give 8-arylacenaphtho[1,2-b]pyridines 18a-b and bis(acenaphtho)-annulated pyridine 20. Heterocyclization of 2 with bifunctional nucleophiles such as 2-picolyllithium and guanidinium nitrate afforded the corresponding acenaphtho[1,2-b]quinolizinium salt 23 and acenaphtho[1,2-d]pyrimidine 24, respectively, in high yields. Finally, acenaphtho[1,2-c]-fused five-membered heterocycles such as 7-(methylthio)acenaphtho[1,2-c]thiophene (25), 7-(methylthio)acenaphtho[1,2-c]furan (27) and 7-(methylthio)acenaphtho[1,2-c] pyrrole-2-carboxylic acid (30) were obtained in good yields by subjection of 2 to Simmons-Smith reaction conditions or by treatment with dimethylsulfonium methylide or glycinate dianion. Some of these newly synthesized PAHs or fused heterocycles were subjected to Raney Ni desulfurization to furnish sulfurfree compounds. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
Semivolatile and volatile compounds in combustion of polyethylene
Font, Rafael,Aracil, Ignacio,Fullana, Andrés,Conesa, Juan A.
, p. 615 - 627 (2007/10/03)
The evolution of semivolatile and volatile compounds in the combustion of polyethylene (PE) was studied at different operating conditions in a horizontal quartz reactor. Four combustion runs at 500 and 850°C with two different sample mass/air flow ratios and two pyrolytic runs at the same temperatures were carried out. Thermal behavior of different compounds was analyzed and the data obtained were compared with those of literature. It was observed that α,ω-olefins, α-olefins and n-paraffins were formed from the pyrolytic decomposition at low temperatures. On the other hand, oxygenated compounds such as aldehydes were also formed in the presence of oxygen. High yields were obtained of carbon oxides and light hydrocarbons, too. At high temperatures, the formation of polycyclic aromatic hydrocarbons (PAHs) took place. These compounds are harmful and their presence in the combustion processes is related with the evolution of pyrolytic puffs inside the combustion chamber with a poor mixture of semivolatile compounds evolved with oxygen. Altogether, the yields of more than 200 compounds were determined. The collection of the semivolatile compounds was carried out with XAD-2 adsorbent and were analyzed by GC-MS, whereas volatile compounds and gases were collected in a Tedlar bag and analyzed by GC with thermal conductivity and flame ionization detectors.
