Commercially available reagents were purchased from commercial sources and used as received without further purification. If no further details are given, the reaction was performed under ambient atmosphere and temperature. Analytical thin layer chromatography (TLC) was performed on silica gel-coated plates (Merck, 60 F254) with the indicated solvent mixture, and visualization was performed using ultraviolet (UV) irradiation (λ = 254 nm) and/or staining with aqueous KMnO4. If not specially mentioned, flash column chromatography used silica gel (200–300 mesh) supplied by Tsingtao Haiyang Chemicals (Qingdao, China).
1H NMR spectra were recorded on a Bruker Avance III 400 (400 MHz) spectrometer. TMS (δH 0.00) were used as the internal reference. 13C NMR spectra were recorded on a Bruker Advance III 400 (100 MHz) spectrometer in CDCl3 (δC 77.16) using their central resonance as the internal reference. All 13C NMR spectra were proton decoupled. High-resolution mass spectra (HRMS) were recorded on a Waters Xevo G2 QTOF MS. A commercially available UV lamp (model: Philips TUV 25W/G25 T8, emission wave-length range: 200–280 nm; λmax: 254 nm) was used as light resource.
1H NMR spectra were recorded on a Bruker Avance III 400 (400 MHz) spectrometer. TMS (δH 0.00) were used as the internal reference. 13C NMR spectra were recorded on a Bruker Advance III 400 (100 MHz) spectrometer in CDCl3 (δC 77.16) using their central resonance as the internal reference. All 13C NMR spectra were proton decoupled. High-resolution mass spectra (HRMS) were recorded on a Waters Xevo G2 QTOF MS. A commercially available UV lamp (model: Philips TUV 25W/G25 T8, emission wave-length range: 200–280 nm; λmax: 254 nm) was used as light resource.