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361.
o-Quinodimethane (o-QDM) generated from benzosultine was used to extend the pyrrole system for the preparation of octabromo-tetranaphtho[2,3]porphyrins via oxidative aromatization. The properties of these bromoporphyrins were presented and chemical transformation via Pd-catalyzed Suzuki reaction was also effectively achieved. 相似文献
362.
M Nakamura H Tahara K Takahashi T Nagata H Uoyama D Kuzuhara S Mori T Okujima H Yamada H Uno 《Organic & biomolecular chemistry》2012,10(34):6840-6849
Benzene-fused bis-(borondipyrromethene)s (bis-BODIPYs) were synthesized by retro-Diels-Alder reaction of the corresponding bicyclo[2.2.2]octadiene-fused (BCOD-fused) bis-BODIPYs, which were, in turn, prepared from 4,8-ethano-4,8-dihydropyrrolo[3,4-f]isoindole derivatives. The π-fused bis-BODIPY chromophores were designed to show intensive absorption and strong fluorescence in the near-infrared region and not to have any strong absorption in the visible region. A 6,10-dibora-5a,6a,9a,10a-tetraaza-s-indaceno[2,3-b:6,5-b']difluorene derivative (syn-bis-benzoBODIPY) obtained by a thermal retro-Diels-Alder reaction of the corresponding BCOD-fused BODIPY dimer has strong absorption and emission bands at 775 and 781 nm, respectively. The absolute quantum yield is 0.36. The absorption is more than 5.0 times stronger than other absorptions observed in the visible region. In the case of 6,15-dibora-5a,6a,14a,15a-tetraaza-s-indaceno[2,3-b:6,7-b']difluorene derivatives (anti-bis-benzoBODIPY), the absorption and emission maxima exceed 840 nm. 相似文献
363.
Kamimura A Miyazaki K Suzuki S Ishikawa S Uno H 《Organic & biomolecular chemistry》2012,10(22):4362-4366
Optically active ent-calystegine B4 was prepared in 13 steps from commercially available chiral L-dimethyl tartrate. The synthesis was achieved by the Michael addition and the aldol reaction of nitromethane to form cycloheptanone in a stereoselective manner. Reduction of the nitro group in the presence of Boc(2)O accomplished an efficient conversion to amino cycloheptanone, which readily afforded the desired ent-calystegine B4. 相似文献
364.
Gokulnath S Toganoh M Yamaguchi K Mori S Uno H Furuta H 《Dalton transactions (Cambridge, England : 2003)》2012,41(20):6283-6290
Singly N-confused [26] and [28]hexaphyrins (4, 5) with planar and twisted structures, respectively, were prepared via the acid catalyzed [3 + 3] condensation of N-confused and regular tripyrrane precursors. Hückel aromaticity is observed for [26]hexaphyrin, while the [28]hexaphyrin and its mono-Pd(II) complex exhibit "nonaromaticity" in spite of their M?bius-type structures, judging from the spectroscopic features and theoretical calculations. 相似文献
365.
Yamada H Kushibe K Okujuma T Uno H Ono N 《Chemical communications (Cambridge, England)》2006,(4):383-385
5-Alkenyl-15-alkynylporphyrins have been obtained unexpectedly by [2 + 2] acid-catalyzed condensation of dipyrrylmethane and TMS propynal in addition to 5,15-dialkynylporphyrin, and the unsymmetrical porphyrin can be converted to a butadiyne-linked dimer by selective desilylation of the alkynyl TMS. 相似文献
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