Nicolet is50 advanced spectrometer

Melting points were determined with a Büchi capillary apparatus and are uncorrected. ¹H and ¹³C NMR spectra were recorded on a Bruker Bio Spin Avance III 600 MHz spectrometer or a Bruker Avance II 500 MHz spectrometer. Chemical shifts are reported in ppm (δ) relative to tetramethylsilane. D₂O was employed to confirm exchangeable protons (ex). Splitting multiplicities are reported as singlet (s), broad signal (bs), doublet (d), double doublet (dd), triplet (t), triplet of doublets (td), quartet (q) and multiplet (m). Diamond ATR-FTIR (attenuated total reflectance Fourier-transform infrared spectroscopy) spectra were acquired using a Nicolet iS50 Advanced Spectrometer (Thermo Scientific); the signal intensity is indicated as strong (s) or medium (m). High-resolution mass spectrometry (HRMS) was performed with a Xevo G2S Q-TOF (Waters Corp). Elemental analyses were determined in a Carlo Erba EA 1108 Analyzer. Reagents, solvents, and starting materials were purchased from standard sources and purified according to literature procedures.