A novel, practical and metal-free approach for the regioselective selenation of coumarins employing (bis(trifluoroacetoxy)iodo)benzene (PIFA) at room temperature is presented. The developed method is suitable for a wide substrate scope and affords 3-selenyl coumarins in good to excellent yields with high selectivity. A radical mechanism is proposed for this new transformation. Furthermore, the application
Rhodium-catalyzed C-H bond activation for the synthesis of quinonoid compounds: Significant Anti-Trypanosoma cruzi activities and electrochemical studies of functionalized quinones
作者:Guilherme A.M. Jardim、Thaissa L. Silva、Marilia O.F. Goulart、Carlos A. de Simone、Juliana M.C. Barbosa、Kelly Salomão、Solange L. de Castro、John F. Bower、Eufrânio N. da Silva Júnior
DOI:10.1016/j.ejmech.2017.05.011
日期:2017.8
synthesized by rhodium-catalyzed C-H bond activation and palladium-catalyzed cross-coupling reactions, were evaluated against bloodstream trypomastigotes of T. cruzi. We have identified fifteen compounds with IC50/24 h values of less than 2 μM. Electrochemical studies on A-ring functionalized naphthoquinones were also performed aiming to correlate redox properties with trypanocidal activity. For instance
aqueous NaOH was found to be a good method for the generation of phenylselenideion. A variety of 2-halogeno-1,4-naphthoquinones and halogenoquinolinequinones were efficiently converted into the corresponding seleno compounds. Selenenylation of 2,3-dichloro-1,4-naphthoquinone gave 2,3-bis(phenylseleno)-1,4-naphthoquinone. The reaction of 2-bromo-1,4-napthoquinone afforded 2,3-bis(phenylseleno)naphthoquinone
Synthesis of Selenium-Quinone Hybrid Compounds with Potential Antitumor Activity via Rh-Catalyzed C-H Bond Activation and Click Reactions
作者:Guilherme Jardim、Daisy Lima、Wagner Valença、Daisy Lima、Bruno Cavalcanti、Claudia Pessoa、Jamal Rafique、Antonio Braga、Claus Jacob、Eufrânio da Silva Júnior、Eduardo da Cruz
DOI:10.3390/molecules23010083
日期:——
were synthesized using rhodium-catalyzed C-H bond activation and click reactions. All compounds were evaluated against five types of cancer cell lines: HL-60 (human promyelocytic leukemia cells), HCT-116 (human colon carcinoma cells), SF295 (human glioblastoma cells), NCIH-460 (human lung cells) and PC3 (human prostate cancer cells). Some compounds showed good activity with IC50 values below 1 µM.
Carbazoloquinone alkaloids are of great interest as privileged structures for anticancer drug molecules. The purpose of this study was to investigate the structure-activity relationships of carbazoloquinone derivatives as anticancer agents. A series of carbazoloquinones including murrayaquinone A, koeniginequinones A and B, and related analogues were therefore prepared. Palladium-catalyzed intramolecular