Derivatives of Fluorene. XXI. New Halogenofluorenes. II.^1a Further Potential Antitumor Agents

Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

“…Numerous biological activities have been reported for natural fluorenones, e.g., antioxidative properties of dendroflorin ( 1c ) and nobilone ( 1d ) [ 6 ], antiischemic activity of caulophine ( 1e ) [ 7 ], and anti-HIV activity of gramniphenol D ( 1g ) and related gramniphenol E ( 1h ) [ 8 ]. For synthetic fluorenones antitumoral [ 9 ], antiviral [ 10 ], and trypanocidal [ 11 ] activities have been reported, and tilorone ( 1i ), an antiviral fluorenone launched about 50 years ago, is presently discussed as a therapeutic option for fighting Ebola and SARS-CoV-2 viruses [ 12 ]. Modifications of the tilorone scaffold resulted in compounds having cytokine-inducing [ 13 ], antitumor [ 14 ], and telomerase-inhibitory effects [ 15 ].…”

2,3‐Disubstituted Fluorene Scaffold for Efficient Green Phosphorescent Organic Light‐Emitting Diodes

“…[80][81][82][83] There are only a few studies on other types of disubstituted fluorene derivatives, [84] even though the corresponding disubstituted fluorenones have been reported. [85][86][87][88][89][90][91] Here we study several new members of fluorene family based on the functionalization of the 2-and 3-positions in fluorene backbone. We design and synthesize four novel fluorene derivatives by introducing of triphenylamine (TPA) or N-phenyl-carbazole (PhCz) units with electron donating properties and 2,4,6-triphenyl-1,3,5-triazine (TRz) segment with electron withdrawing properties in fluorene at different substituent positions.…”

“…The research on disubstituted fluorene derivatives mostly focused on the 9,9′‐position, [76–79] 2,7‐position, [68–73] and 3,6‐position of fluorene [80–83] . There are only a few studies on other types of disubstituted fluorene derivatives, [84] even though the corresponding disubstituted fluorenones have been reported [85–91] …”

Electrochemical two-electron oxygen reduction reaction (ORR) induced aerobic oxidation of α-diazoesters

“…The structure of the product 2bg was also unequivocally established by an X-ray single-crystal analysis. In light of the importance of cyclandelate as biological and pharmacological activities such as calcium-channel antagonism, inhibitory effects on hepatic-CoA reductase, as vasodilators drug for a direct-acting smooth muscle relaxant, 12 we extended the studies of the present protocol for the synthesis of cyclandelate. The cyclandelate precursor 4 was easily obtained under our electrochemical conditions in good yield (1 mmol scale reaction was also performed using the established electrochemical strategy, for more details, see the Supplementary Information), and cyclandelate was then synthesized by I 2 -HSiEt 3 reduction system in 67% yield as a mixture of several diastereomers (Scheme 3) (Scheme 4).…”