1-Nitro-3,5-bis(trifluoromethyl)benzene

CLEAR YELLOW LIQUID

Reactions employing TBAF generated in situ in accordance with the method of the invention are summarized in Table 2. For nucleophilic fluorination, anhydrous TBAF is comparable to, or exceeds the reactivity of other nucleophilic fluorinating agents. In head-to-head comparisons, TBAF exhibits dramatically enhanced rates of fluorination compared to dynamic vacuum dried 'anhydrous' TBAF, CoCp2F, or TBAT. Neither heating nor a gross excess of TBAF is generally required to effect substitution (Table 2).; General Procedure for Fluorination Reactions; The general procedure given below was used for all fluorination reactions employing in situ generated TBAF. Yields were calculated by integration of the relevant peaks in the 1H and 19F NMR spectra. In an NMR tube equipped with a PTFE resealable closure, TBACN (0.134 g, 0.5 mmol) was dissolved in anhydrous CD3CN (or (CD3)2SO) (0.5 ml). At 25 C., 9.6 mul (0.083 mmol) C6F6 was added, and the mixture was held at room temperature for 1 h. The mixture was cooled to -40 C. and the substrate (0.25-0.5 mmol) was added. The solution was mixed vigorously and the tube was transferred to a precooled (-35 C.) NMR probe and spectra were gathered. The time elapsed from the sample mixing until completion of the first NMR spectrum was approximately 3 min. The reaction was monitored by 19F NMR spectra every 2 minutes until no further change was observed.General procedure: A glass culture tube containing a magnetic stir bar was charged with a nitroarene substrate and boronic acid, then fitted with a PTFE-lined silicone septum within a phenolic screw-thread open-top cap after wrapping the reaction tube thread once with Teflon tape. The vessel was evacuated and backfilled with nitrogen on a Schlenk line. Dry m-xylene (2 mL, 0.5 M) was added via syringe, followed by triethylphosphine (0.44 mL, 3 equivalents) and the reaction mixturewas heated 120 C with stirring. Upon completion, the reaction mixture was cooled to ambient temperature then diluted with 10 mL of distilled water. With the aid of ethyl acetate (ca. 3 x 10 mL), the reaction mixture was transferred to a separatory funnel. After mixing and separating the phases, the organic layer was washed with 10 mL of a 1M NaOH aqueous solution, and 10 mL of brine. Each aqueous phase was back-extracted with one 10 mL portion of ethyl acetate. The combined organic layers were dried over anhydrous sodium sulfate, filtered and concentrated by rotary evaporation. The crude residues were purified via column chromatography to yield pure coupling products. Columns were primarily slurry packed with hexanes and mobile phase polarity was increased gradually to the mixture indicated. Note: hexanes = Hex, dichloromethane = DCM, ethyl acetate = EA.

Molecular Weight:259.10
XLogP3:4.1
Hydrogen Bond Acceptor Count:8
Exact Mass:259.00679731
Monoisotopic Mass:259.00679731
Topological Polar Surface Area:45.8
Heavy Atom Count:17
Complexity:272
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes