4.1. General Remarks for the Synthetic Procedure

Solvents were dried by distillation before use. All reactions were carried out in dried glassware. The melting points of the compounds were determined in open capillaries and are uncorrected. High quality infrared spectra (64 scans) were obtained at 2 cm⁻¹ resolution with an FT-IR Bruker (Billerica, MA, USA) Alpha System spectrometer. All spectra were obtained in 3 mM solutions in CH₂Cl₂. All compounds were dried in vacuo and all the sample preparations were performed in a nitrogen atmosphere. NMR spectra were recorded with a Varian (Palo Alto, CA, USA) Inova 400 spectrometer at 400 MHz (¹H NMR), at 100 MHz (¹³C NMR), and at 376.5 MHz (¹⁹F NMR). Chemical shifts are reported in δ values relative to the solvent peak. HPLC-MS was used to check the purity of compounds.