746-47-4Relevant articles and documents
-
Yano et al.
, p. 2739 (1979)
-
REACTIONS OF 1-OXA-3-AZONIABUTATRIENE SALTS WITH 1,3-DIPOLES
Hamed, Atef,MueLler, Edgar,Jochims, Johannes C.,Zsolnai, Laszlo,Huttner, Gottfried
, p. 5825 - 5836 (1989)
The nitrile N-oxide 4 undergoes a reversible cycloaddition to the carbonyl group of the 1-oxa-3-azoniabutatriene salts 3a-c to give the geminal dioxy substituted 2-azoniaallene salts 5a-c.Azibenzil 7 and 3a,d afford the 2-azoniaallene salts 8a,d.With the nitrone 11 the cumulene 3d reacts to yield the open-chain addition product 12.The salt 3a reacts with two equivalents of diazofluorene to give the β-lactamium salt 13, which can be hydrolyzed to afford the N-formyl-β-lactam 15.X-ray structural analyses of 5b and 8d confirm the proposed constitutions.
Structural influences impacting the role of the 9-ylidene bond in the electronic tuning of structures built upon 9-fluorenylidene scaffolds
Eakins, Galen L.,Cooper, Matthew W.,Gerasimchuk, Nikolay N.,Phillips, Terry J.,Breyfogle, Bryan E.,Stearman, Chad J.
, p. 1059 - 1071 (2013)
A structure-effect study is presented pertaining to the HOMO-LUMO tuning of compounds built upon the 9-fluorenylidene scaffold frequently incorporated as a moiety within organic-based semiconducting materials. The results represent the first reported analysis employing an ensemble of spectroscopy, electrochemistry, and crystal structure data to elucidate and compare the electronic properties of 9-fluorenones, 9-fluorenylidenes, and 9-fluorenimine derivatives. The results also provide the first spectroscopically and crystallographically measured description of exciton coupling within 9,9′-bifluorenylidenes. The 9-ylidene bond is seen to play a key role impacting the electronic properties, and an examination of the effects of substituents, conjugation, heteroatoms, and steric strain on the 9-ylidene bond in a diverse set of structures with representative structural variations relevant to the HOMO-LUMO tuning is presented. Increasing conjugation decreased the HOMO-LUMO gap (HLG), increased the HOMO energy (EHOMO), but decreased the LUMO energy (ELUMO). Substituent effects were observed to produce only slight changes that tended to decrease the HLG and increase both EHOMO and ELUMO, while heteroatom inclusion at the 9-ylidine bond tended to decrease the HLG, EHOMO, ELUMO, and the extinction coefficient. In the sterically hindered 9,9′- bifluorenylidenes, increased steric strain that promoted either an increase in the torsion angle or bond length of the 9-ylidene bond was seen to decrease the HLG via exciton coupling. These results elucidate the HOMO-LUMO tuning of systems containing a 9-fluorenylidene moiety and may assist in developing materials with specifically tuned HLGs and HOMO-LUMO levels for a variety of applications.
The reaction of electrophilic terminal phosphinidene complexes with benzophenone and fluorenone: The unexpected formation of six- and eight-membered heterocycles
Inubushi, Yoichi,Huy, Ngoc Hoa Tran,Ricard, Louis,Mathey, Francois
, p. 83 - 86 (1997)
The phenylphosphinidene-pentacarbonyltungsten complex 2, as generated from the appropriate 7-phosphanorbornadiene complex 1, reacts at 60°C with benzophenone to give a benzo-annellated 1-oxa-2-phosphacyclohex-4-ene 2-oxide as a 1:1 mixture of two isomers 3a,b. The same phosphinidene complex 2 reacts at 120°C with fluorenone. A deoxygenation of fluorenone takes place leading to the bifluorenylidene 4 and to an eight-membered 1,2,8-oxadiphosphocane 2,8-dioxide 5. Both compounds 3b and 8 have been fully characterized by X-ray crystal structure analysis. The two reactions are interpreted as resulting from the initial formation of a P ... O Lewis adduct between the phosphinidene and the ketone.
Trivalent organophosphorus reagent induced pinacol rearrangement of 4H-cyclopenta[2,1-b:3,4-b′]dithiophen-4-one
Marin, Lidia,Zhang, Yuexing,Robeyns, Koen,Champagne, Beno?t,Adriaensens, Peter,Lutsen, Laurence,Vanderzande, Dirk,Bevk, David,Maes, Wouter
, p. 526 - 529 (2013)
In this Letter we report on the reaction of 4H-cyclopenta[2,1-b:3,4- b′]dithiophen-4-one with various trivalent organophosphorus derivatives, with an emphasis on the final products depending on the applied reagents. No reaction occurred upon treatment with either triphenyl- or tricyclohexylphosphine, whereas addition of triethyl phosphite or tri(n-butyl)phosphine resulted in pinacol rearrangement. Structure elucidation of the isolated 5H-spiro(benzo[1,2-b:6,5-b′]dithiophene-4,4′- cyclopenta[2,1-b:3,4-b′]dithiophen)-5-one was achieved by combined NMR experiments, theoretical chemical shift and geometry calculations, and single crystal X-ray analysis.
Inclusion crystals of 2,2′,7,7′,9,9′-hexahalo-9,9′-bisfluorenyl derivatives: a new family of polyhalo aryl hosts
Tanaka, Koichi,Wada, Shin-ichi,Caira, Mino R.
, p. 9213 - 9220 (2007)
The preparation and inclusion properties of the new halo aryl hosts, 2,2′,7,7′,9,9′-hexahalo-9,9′-bisfluorenyl derivatives 5-7, are described. The host compounds 5-7 having four halogen atoms on the aromatic rings form stable inclusion crystals with many guest compounds, whereas the parent compound 4 does not. The X-ray structures of the host 4 and representative inclusion compounds of hosts 5-7 were determined, allowing rationalization of several of the experimental observations.
α-Bromoacrylic Acids as C1 Insertion Units for Palladium-Catalyzed Decarboxylative Synthesis of Diverse Dibenzofulvenes
Zhang, Minghao,Deng, Wenbo,Sun, Mingjie,Zhou, Liwei,Deng, Guobo,Liang, Yun,Yang, Yuan
, p. 5744 - 5749 (2021/08/18)
Herein α-bromoacrylic acids have been employed as C1 insertion units to achieve the palladium-catalyzed [4 + 1] annulation of 2-iodobiphenyls, which provides an efficient platform for the construction of diverse dibenzofulvenes. This protocol enables the formation of double C(aryl)-C(vinyl) bonds via a C(vinyl)-Br bond cleavage and decarboxylation. It is particularly noteworthy that the method features a broad substrate scope, and various interesting frameworks, such as bridged ring, fused (hetero)aromatic ring, and divinylbenzene, can be successfully incorporated into the products.
Nickel-catalyzed synthesis of 9-monoalkylated fluorenes from 9-fluorenone hydrazone and alcohols
Fan, Jiang-Tao,Fan, Xin-Heng,Chen, Yong-Jie,Gao, Cai-Yan,Yang, Lian-Ming
, p. 2895 - 2902 (2019/08/12)
A practical protocol was disclosed for the nickel-catalyzed C-alkylation of 9-fluorenone hydrazone with alcohols using t-BuOK as the base, and 9-monoalkylated fluorene derivatives were obtained in good yields under the benign conditions.
