Reactions were monitored through thin-layer
chromatography (TLC) with commercial silica gel plates (Merck silica
gel, 60 F254). Visualization of the developed plates was performed
under UV lights at 254 nm and by staining with cerium ammonium molybdate,
2,4-dinitrophenylhydrazine and vanillin stains. Flash column chromatography
was performed on silica gel 60 (40–63 μm) as stationary
phase. Preparative TLCs were conducted on PLC silica gel 60 F254,
1 mm.1H NMR spectra were recorded at 300 MHz, 13C NMR spectra were recorded at 75 MHz and 19F spectrum
was recorded at 282 MHz in a 300 MHz Varian Mercury spectrometer,
using CDCl3 as solvent. Chemical shifts (δ) are reported
in ppm referenced to the CDCl3 residual peak (δ 7.26) or TMS
peak (δ 0.00) for 1H NMR and to CDCl3 (δ
77.16) for 13C NMR. The following abbreviations were used
to describe peak splitting patterns: s = singlet, d = doublet, t =
triplet, m = multiplet. Coupling constants, J, were
reported in Hertz (Hz). High-resolution mass spectra were recorded
on a Waters ESI-TOF MS spectrometer. Tetrahydrofuran (THF) was dried
by distillation under argon with sodium metal and benzophenone as
indicator. Dichloromethane (DCM) was dried by distillation under argon
with calcium hydride. Isotope labeled oxygen-18 (99% isotopic purity)
was purchased from Sigma-Aldrich (CAS Number 32767–18–3).
A small balloon was filled with oxygen-18 and used directly in the
oxidation reaction.
chromatography (TLC) with commercial silica gel plates (Merck silica
gel, 60 F254). Visualization of the developed plates was performed
under UV lights at 254 nm and by staining with cerium ammonium molybdate,
2,4-dinitrophenylhydrazine and vanillin stains. Flash column chromatography
was performed on silica gel 60 (40–63 μm) as stationary
phase. Preparative TLCs were conducted on PLC silica gel 60 F254,
1 mm.1H NMR spectra were recorded at 300 MHz, 13C NMR spectra were recorded at 75 MHz and 19F spectrum
was recorded at 282 MHz in a 300 MHz Varian Mercury spectrometer,
using CDCl3 as solvent. Chemical shifts (δ) are reported
in ppm referenced to the CDCl3 residual peak (δ 7.26) or TMS
peak (δ 0.00) for 1H NMR and to CDCl3 (δ
77.16) for 13C NMR. The following abbreviations were used
to describe peak splitting patterns: s = singlet, d = doublet, t =
triplet, m = multiplet. Coupling constants, J, were
reported in Hertz (Hz). High-resolution mass spectra were recorded
on a Waters ESI-TOF MS spectrometer. Tetrahydrofuran (THF) was dried
by distillation under argon with sodium metal and benzophenone as
indicator. Dichloromethane (DCM) was dried by distillation under argon
with calcium hydride. Isotope labeled oxygen-18 (99% isotopic purity)
was purchased from Sigma-Aldrich (CAS Number 32767–18–3).
A small balloon was filled with oxygen-18 and used directly in the
oxidation reaction.
