- Highly Deformed o-Carborane Functionalised Non-linear Polycyclic Aromatics with Exceptionally Long C?C Bonds
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The effect of substituting o-carborane into the most sterically hindered positions of phenanthrene and benzo(k)tetraphene is reported. Synthesised via a Bull–Hutchings–Quayle benzannulation, the crystal structures of these non-linear acenes exhibited the highest aromatic deformation parameters observed for any reported carborane compound to date, and among the largest carboranyl C?C bond length of all organo-substituted o-carboranes. Photoluminescence studies of these compounds demonstrated efficient intramolecular charge-transfer, leading to aggregation induced emission properties. Additionally, an unusual low-energy excimer was observed for the phenanthryl compound. These are two new members of the family of carborane-functionalised non-linear acenes, notable for their peculiar structures and multi-luminescent properties.
- Marsh, Adam V.,Little, Mark,Cheetham, Nathan J.,Dyson, Matthew J.,Bidwell, Matthew,White, Andrew J. P.,Warriner, Colin N.,Swain, Anthony C.,McCulloch, Iain,Stavrinou, Paul N.,Heeney, Martin
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supporting information
p. 1970 - 1975
(2020/12/25)
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- Oxidative, Iodoarene-Catalyzed Intramolecular Alkene Arylation for the Synthesis of Polycyclic Aromatic Hydrocarbons
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A catalytic, metal-free and chemoselective oxidative intramolecular coupling of arene and alkene C?H bonds is reported. The active hypervalent iodine (HVI) reagent, generated catalytically in situ from iodotoluene and meta-chloroperoxybenzoic acid (m-CPBA), reacts with o-vinylbiphenyls to generate polyaromatic hydrocarbons in up to 95 % yield. Experimental evidence suggests the reactions proceed though vinyliodonium and, possibly, vinylenephenonium intermediates.
- Zhao, Zhensheng,Britt, Liam H.,Murphy, Graham K.
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p. 17002 - 17005
(2018/11/01)
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- New reactivity patterns of copper(I) and other transition metal NHC complexes: application to ATRC and related reactions
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Pre-formed transition metal-NHC complex is shown to be an effective catalyst for Atom Transfer Radical Cyclisation (ATRC) reactions.
- Bull, James A.,Hutchings, Michael G.,Luján, Cristina,Quayle, Peter
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p. 1352 - 1356
(2008/09/18)
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- An unusual decarboxylative benzannulation and biaryl formation during copper(I)-promoted halogen atom transfer radical cyclization of 2-allylaryl trichloroacetates
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CuCl/bpy-promoted halogen atom transfer radical cyclization of 2-allylaryl trichloroacetates in refluxing benzene gave benzannulated chloroarenes and benzannulated symmetrical biaryls along with reductive dehalogenation products. The unusual decarboxylative benzannulation and biaryl formation might be explained by a further intramolecular radical addition on the benzene ring of the eight-membered lactone intermediate, initially formed through 8-endo-trig halogen atom transfer radical cyclization, followed by decarboxylation, radical dimerization and dehydrochlorination reactions.
- Ram, Ram N.,Tittal, Ram K.,Upreti, Shailesh
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p. 7994 - 7997
(2008/03/14)
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- A remarkably simple and efficient benzannulation reaction
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(Chemical Equation Presented) On a short fuse: Although fused aromatic rings are common structural motifs in natural products, there are relatively few direct methods for the preparation of such systems from acyclic precursors. An atom-transfer radical cyclization carried out under microwave (MW) irradiation has now been developed which gives rapid access to functionalized aromatic compounds from readily available starting materials (see scheme).
- Bull, James A.,Hutchings, Michael G.,Quayle, Peter
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p. 1869 - 1872
(2008/03/12)
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- PROCESS FOR SYNTHESIS OF AROMATIC COMPOUNDS
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The present invention refers to a process for preparing a compound of the formula (I) wherein R denotes an organic radical which, together with the two carbon atoms to which it is bonded, forms a carbocyclic or heterocyclic ring; R1, R2, R3 and X, independently, denote hydrogen, halogen, nitro, cyano or an organic radical; or R1 and R2 or R2 and R3, together with the carbon atoms to which they are bonded, form a ring; which comprises exposing a compound of the formula (II) wherein R1, R2, R3 and X are defined as given above and Y and Z, independently, have one of the meanings of X; to an energy source in the presence of a catalyst system.
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Page/Page column 12-13
(2008/06/13)
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- Benzannulated Isobenzofurans
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A number of arynes, generated by treatment of haloarenes with sodium or potassium amide in tetrahydrofuran, were trapped with furan.The resulting dihydro epoxy arenes were converted into the following annulated isobenzofuran derivatives by using reverse Diels-Alder methodology: naphthofuran, phenanthrofuran, pyrenofuran, pyrenofuran, anthrafuran, phenanthrofuran and phenathrofuran.Bimolecular rate constants for the addition of maleic anhydride to these furans were measured, and were correlated with the Herndon structure count.Addition of arynes to selected members of this furan series yielded adducts which were deoxygenated to afford polycyclic aromatic hydrocarbons.
- Moursounidis, John,Wege, Dieter
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p. 235 - 249
(2007/10/02)
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