- Site-Specific Synthesis of Carbazole Derivatives through Aryl Homocoupling and Amination
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We synthesized various carbazoles from anilines through a three-step process with good overall yields (up to 48percent). This process comprises N -acetylation, copper(0)-mediated Ullmann homocoupling, and acid-mediated intramolecular amination. It permits various functional groups on the substrate. Scale-up of the developed three-step synthetic route to carbazoles was also demonstrated.
- Baek, Junghyun,Ban, Jaeyoung,Lim, Minkyung,Rhee, Hakjune,Shabbir, Saira
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p. 917 - 927
(2020/03/13)
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- Quinoline synthesis: Scope and regiochemistry of photocyclisation of substituted benzylidenecyclopentanone O-alkyl and O-acetyloximes
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Irradiation of substituted 2-benzylidenecyclopentanone O-alkyl and O-acetyloximes in methanol provides a convenient synthesis of alkyl, alkoxy, hydroxy, acetoxy, amino, dimethylamino and benzo substituted annulated quinolines. para-Substituents yield 6-substituted-2,3-dihydro-1H-cyclopenta[b] quinolines with 8-substituted products being obtained from ortho-substituted starting materials. Reactions of meta-substituted precursors are highly regioselective, with alkyl substituents leading to 5-substituted 2,3-dihydro-1H-cyclopenta[b]quinolines and more strongly electron-donating substituents generally resulting in 7-substituted products. 2-Furylmethylene and 2-thienylmethylene analogues yield annulated furo- and thieno-[2,3e]pyridines respectively. Sequential E- to Z-benzylidene group isomerisation and six π-electron cyclisation steps result in formation of a short-lived dihydroquinoline intermediate which spontaneously aromatises by elimination of an alcohol or acetic acid. For 2-benzylidenecyclopentanone O-allyloxime, singlet excited states are involved in both steps. The Royal Society of Chemistry 2007.
- Austin, Mark,Egan, Oliver J.,Tully, Raymond,Pratt, Albert C.
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p. 3778 - 3786
(2008/10/09)
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- Synthesis of butadiyne-bridged [4n] metacyclophanes having exo-annular t-butyl groups
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Butadiyne-bridged [44]- and [48]metacyclophanes having exo-annular t-butyl groups were prepared by intermolecular Eglinton coupling of the dimeric unit or by intramolecular ring closure of the linear tetramer. Comparison of the 1H and 13C NMR spectra of [44]metacyclophane with those of [48]cyclophane and diphenylbutadiyne revealed its prominent geometrical feature due to deformation of the triple bonds from linearity. The [44]Metacyclophane was converted into [08]thiophenometacyclophane in good yield by treatment with sodium sulfide.
- Tobe, Yoshito,Utsumi, Naoto,Nagano, Atsushi,Sonoda, Motohiro,Naemura, Koichiro
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p. 8075 - 8083
(2007/10/03)
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- AROMATIC ACETYLCHOLINESTERASE INHIBITORS
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Compounds of general formula (I), stereosiomers and pharmaceutically acceptable salts thereof, wherein each of Z and Z' are independently H or F; Q is (a), CH(OH), (b); X is H, Br, Cl, F or CF3 ; Y is H, Br, Cl, F, OH, OR5, OC(O)R4, N3, CN, NO2, SO3 H, CO
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- Synthesis and self-association properties of diethynylbenzene macrocycles
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We synthesized diethynylbenzene macrocycles (DBMs), cyclic oligomers of diethynylbenzene, having functional groups in the periphery of the macrocyclic framework and investigated their self-association properties in solution resulting from π-π stacking interaction. The tetrakis-DBM having hexadecyl ester groups showed dimerization behavior not only in chloroform-d, but also in o-dichlorobenzene-4.
- Tobe, Yoshito,Utsumi, Naoto,Kawabata, Kazuya,Naemura, Koichiro
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p. 9325 - 9328
(2007/10/03)
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