Mimicking the biological activity of diazobenzo[b]fluorene natural products with electronically tuned diazofluorene analogs
作者:Wei Zeng、T. Eric Ballard、Alexander G. Tkachenko、Virginia A. Burns、Daniel L. Feldheim、Christian Melander
DOI:10.1016/j.bmcl.2006.07.024
日期:2006.10
Under appropriate electronic modulation, simple diazofluorene analogs recapitulate the DNA cleavage activity of kinamycin D under thiol-based reducing conditions. Achieving DNA cleavage under these reducing conditions is key to anticancer activity, as the most active compound, 1-methoxydiazofluorene, inhibits the proliferation of HeLa cells.
Microwave-assisted intramolecular palladium-mediated cyclizations of <i>o</i>-iodobenzophenones for methoxy fluoren-9-ones
作者:Reda A. Haggam
DOI:10.1080/00397911.2022.2095210
日期:2022.7.18
irradiation is an effective tool in organic reactions that required long reaction times under thermal conditions. Herein substituted 2-iodobenzophenones were transformed into substituted fluoren-9-ones via cesium carbonate and bis(triphenylphosphine) palladium(II) chloride with 56–92% yields within 30–45 min under microwave irradiations. A remarkable decrease in the reaction time with high yield products was
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.
Annulation Strategies for Benzo[<i>b</i>]fluorene Synthesis: Efficient Routes to the Kinafluorenone and WS-5995 Antibiotics
作者:Ghassan Qabaja、Graham B. Jones
DOI:10.1021/jo0056186
日期:2000.10.1
Intramolecular palladium-mediated arylation approaches to benzo[b]fluorenes have been investigated. The methodology has been applied in a short synthesis of tri-O-methylkinafluorenone, providing an effective alternative td Friedel-Crafts-based approaches. During the course of this work, an acid-promoted quinolactonization of naphthoquinones was also developed, providing direct access to either ortho or para isomers as desired. Application of this methodology in syntheses of the antibiotics WS-5995A, WS-5995C, and functional analogues was demonstrated, and antitumoral activity of this class was determined.
A Simple Approach to the Synthesis of Fluoren-9-Ones
作者:M. M. V. Ramana、Prashant V. Potnis
DOI:10.1080/00397919508015860
日期:1995.6
Cyclohexene-1-Carboxylic acid (I) undergoes reaction with various aromatic substrates (2a-i) in presence of Polyphosphoric acid (PPA) at 100 degrees C to give cis-1,2,3,4,4a,9a-hexahydrofluoren-9-ones (3a-i) in good yield. Dehydrogenation of (3a-i) with selenium powder afforded corresponding fluoren-9-ones (4a-i) in high yield.