Synthesis of indoles with a polyfluorinated benzene ring

An effective two-step synthesis, fluorescent properties, antioxidant activity and cytotoxicity evaluation of benzene-fluorinated 2,2-dimethyl-2,3-dihydro-1H-quinolin-4-ones

“…We have revealed that boiling of ethanolic solution of 3c in the presence of PTSA during 8 h resulted in the totally gumming of the reaction mixture, whereas using MeOH gave 1c with acceptable yield (Table 1, entry 3). An attempt to prepare 1e in boiling EtOH led mainly to earlier known [14] 2-substituited-4,5,6,7-tetrafluoroindole ($90% according to 19 F NMR and GC-MS analysis data) as result of acid-catalyzed intramolecular cyclization of the starting 2-alkynylaniline 3e [15]. Using MeOH suppressed the backside process and gave 3e with acceptable yields (Table 1, entry 5).…”

Aminofluorination of 2-alkynylanilines: a Au-catalyzed entry to fluorinated indoles

“…Recently, 7-fluoroindole has been proposed as a potential candidate for the use in an antivirulence approach against persistent Pseudomonas aeruginosa infections [ 13 ]. Fluorine introduction in the benzene moiety of respective indoles was accomplished through a variety of methods [ 14 ]. 4-Fluoroindole derivatives have been prepared through nucleophilic attack on intermediate 4-indolediazonium salts [ 15 ].…”

The p-toluenesulfonic acid-catalyzed transformation of polyfluorinated 2-alkynylanilines to 2-aminoarylketones and indoles

“…The reaction yields are comparable to those obtained by the KOHpromoted cyclization of polyfluorinated 2-alkynylanilines. 19 …”

“…The reaction of 3ac was accompanied by a noticeable thickening of the reaction mixture, and despite the fact that ketone 4ae was the only product, its yield was low (Entries 11). Deprotection of the THPprotecting group is known to proceed easily even at room temperature, 19 and it is reasonable to assume that in the case of 3ac (and all related compounds), hydration of the triple bond was accompanied by alcoholysis of the CH 2 OTHP fragment.…”

“…Supplementary Material: General methods and procedures, assigned 1 H, 19 F 13 C and NMR spectral data in table form, copies of 1 H, 19 F and 13 C NMR spectra. This material is available.…”