- Palladium-catalyzed intramolecular aromatic C-H acylation of 2-arylbenzoyl fluorides
-
The catalytic intramolecular cyclization of acyl fluorides using a Pd(OAc)2/PCy3 system is described. A wide range of 2-arylbenzoyl fluoride derivatives can be used as fluorenone precursors and the reaction proceeds via an intramolecular coupling between aromatic C-H bonds with acyl C-F bonds. The reaction can be applied to the synthesis of indenofluorenedione derivatives and to the construction of other molecules with fivemembered rings.
- Hayakawa, Kazuki,Ikai, Kana,Ogiwara, Yohei,Sakai, Norio,Sakurai, Yuka
-
p. 1882 - 1893
(2021/08/13)
-
- Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone
-
Highly substituted fluorenones are readily prepared in mostly fair to good yields via metal- and additive-free TBHP-promoted cross-dehydrogenative coupling (CDC) of readily accessible N-methyl-2-(aminomethyl)biphenyls and 2-(aminomethyl)biphenyls. This methodology is compatible with numerous functional groups (methoxy, cyano, nitro, chloro, and SEM and TBS-protective groups for phenols) and was further utilized in the first total synthesis of the natural product nobilone.
- Bracher, Franz,Jourjine, Ilya A. P.,Krau?, Jürgen,Zeisel, Lukas
-
p. 2668 - 2679
(2021/11/30)
-
- Novel syntheses of fluorenones via nitrile-directed palladium-catalyzed C-H and dual C-H bond activation
-
Novel procedures for the [Pd]/[Ag]/TFA system catalyzed cascade reactions of nitrile directed remote C-H and dual C-H bond activation with insertion of nitrile were developed, which afforded variously polysubstituted fluorenones in moderate to good yields with tolerance of a wide variety of substrates.
- Wan, Jung-Chih,Huang, Jun-Min,Jhan, Yu-Huei,Hsieh, Jen-Chieh
-
supporting information
p. 2742 - 2745
(2013/07/19)
-
- On the Transmission of Substituent Effects in Fluorenes and Fluorenones
-
A series of 2- and 2,7-substituted fluorenes (1) and fluorenones (2) were prepared either by electrophilic substitution (1c-f, h-j; 2c, d, j), reduction (1, 2k, l) or nucleophilic exchange (1g, m, n; 2m) via respective diazonium compounds as well as by oxydation (2e-h, n) of the hydrocarbons (1).The carbon-13 n.m.r. spectra for the fluorene (1a-n) and fluorenone (2a-n) derivatives was analyzed using a dual substituent parameter (DSP) equation.The substituent chemical shifts (SCS) of the carbon atoms 4a, 4b, 7 and 4a, 4b, 7, 9 of eleven fluorenes and nine fluorenones,respectively, correlate with the F, R substituent constants and with ?I, ?R0 ones in a satisfactory manner.The comparison indicates that the correlation with the F, R constants yields always a higher resonance contribution than the calculation with ?I, ?R0 constants.The DSP analysis reveals that transmission of the substituent effect to the substituted ring is primarily resonance controlled while the transmission to the second ring involves a ?-bond polarization mechanism.For C-4b in the unsubstituted ring a reversed substituent effect was found.In contrast to fluorenes in fluorenones the transmission of the substituent effect involves the carbon atom 9.
- Hauser, A.,Thurner, J.-U.,Hinzmann, B.
-
p. 367 - 378
(2007/10/02)
-
- Kinetics and Mechanism of Oxidation of Fluoren-9-ol and Substituted Fluoren-9-ols by Bromamine-T
-
The title reactions have been investigated in aq. acetic acid medium both in the presence and absence of perchloric acid.The reactions are first order each in and under both the conditions.There is unit dependence in perchloric acid.The effects of change in polarity of the solvent medium, added toluene-p-sulphonamide and sodium perchlorate have been studied.The reaction exhibits kinetic isotope effect (kH/kD = 2.2).Hammett ρ is found to be -2.8.Activation parameters have been evaluated.A mechanism consistent with rate data has been proposed.
- Gunasekaran, S.,Venkatasubramanian, N.
-
p. 774 - 777
(2007/10/02)
-