Microqtof spectrometer

All reactions were performed under an atmosphere of argon by using standard Schlenk or dry box techniques; solvents were dried over Na metal or CaH₂ under nitrogen atmosphere. (R₃P)AuCl (R = Me, Et) were synthesized using literature procedures^{66 (link)–68 (link)}. ¹H, ¹³C, ²⁹Si, and ³¹P NMR spectra were obtained with a Bruker AV 400 instrument at 400 MHz (¹H NMR), 101 MHz (¹³C NMR) and 162 MHz (³¹P NMR), as well as Bruker AV 500 instrument at 500 MHz (¹H NMR), 126 MHz (¹³C NMR), 99 MHz (²⁹Si NMR), 202 MHz (³¹P NMR) at 298 K. Unless otherwise noted, the NMR spectra were recorded in benzene-d₆ at ambient temperature. The ¹H and ¹³C NMR chemical shifts were referenced to residual ¹H and ¹³C signals of the solvents. NMR multiplicities are abbreviated as follows: s = singlet, d =  doublet, t = triplet, dt = doublet of triplets, m = multiplet, and brs = broad singlet. Coupling constants J are given in Hz. Electrospray ionization (ESI) mass spectra were obtained at the Mass Spectrometry Laboratory at Hangzhou Normal University with a Bruker Daltonics MicroQtof spectrometer. Melting points were measured with a BUCHI Melting Point M-560. Sampling of air-sensitive compounds was carried out using a MBRAUN’s MB-10-G glove box. UV–Vis spectra were recorded on a Shimadzu UV-1800 spectrophotometer.

The reactions were monitored by thin layer chromatography (TLC), which were performed using Merck (Merck, Darmstadt, Germany) silica gel (60 F₂₅₄), with a 0.25 mm thickness. For visualization, TLC plates were either exposed to UV light, or stained with iodine vapor or in a 5% vanillin solution in 10% aqueous H₂SO₄ and heat. Column chromatography was performed using Merck Silica Gel (230–400 mesh). High-resolution mass spectra (HRMS) were recorded in positive ion mode (ESI) using a Bruker microQTOF spectrometer (Bruker, Billerica, MA, USA). Low-resolution mass spectra were obtained with a Shimadzu GC-MS-QP2010 mass spectrometer (Shimadzu Corporation, Kyoto, Japan). NMR spectra were recorded with Bruker DPX (Bruker). (¹H-NMR = 400 and 500 MHz; ¹³C-NMR = 100 and 126 MHz) instruments using CDCl₃ as solvent and calibrated using tetramethylsilane (TMS) as internal standard. Coupling constants (J) were reported in Hertz and chemical shifts (δ) in ppm. The NMR spectra are found in the Supplementary Materials. The reagents (substituted alkynes, sodium tetrahydroborate, elemental chalcogen) and PEG-400 were purchased from Sigma-Aldrich (Sigma-Aldrich, St. Louis, MO, USA).

Ultraviolet spectra were obtained on an UV-1700 spectrophotometer (SHIMADZU, Japan). The IR spectra were measured on a Bruker IFS 55 spectrophotometer (Bruker, Germany). NMR spectra data were recorded using a Bruker ARX-400 spectrometers with standard pulse sequences operating at 400 MHz for ¹H and 100 MHz for ¹³C, respectively, and chemical shifts were expressed with ppm (δ). HRESIMS was detected on a Bruker Micro Q-TOF spectrometer. Column chromatography was performed using MCI gel (CHP20P, 75–150 μm; Mitsubishi Chemical Industries Ltd. Japan), C18 reversed-phase (RP) silica gel (60–80 mm; Merck, Germany), and silica gel (100–200 and 200–300 mesh; Qingdao Marine Chemical Inc. China). Precoated silica gel GF254 plates (Yantai Zifu Chemical Group Co. China) were used for TLC analysis. Semipreparative high performance liquid chromatography was carried out on a Shimadzu LC-6AD HPLC equipped with a SPD-20A UV/VIS detector using a YMC Pack ODS-A column (250 × 10 mm, 5 μm).