Synthesis and Characterization of Chiral Organocatalysts

Commercially available compounds were used without further purification. Solvents were dried according to standard procedures. Column chromatography was performed with silica gel (200–300 mesh). Melting points were determined with an XT-4 melting-point apparatus and are uncorrected. ¹H NMR spectra were measured with a Bruker Ascend 400 MHz spectrometer, chemical shifts are reported in δ (ppm) units relative to tetramethylsilane (TMS) as an internal standard. ¹³C NMR spectra were measured at 100 MHz with a 400 MHz spectrometer or at 176 MHz with a 700 MHz spectrometer, chemical shifts are reported in δ (ppm) units relative to tetramethylsilane and referenced to solvent peak (CDCl₃, δ = 77.00 ppm; DMSO-d₆, δ = 39.43 ppm). High-resolution mass spectra were measured with an Agilent 6520 Accurate-Mass Q-TOF MS system equipped with an electrospray ionization (ESI) source. Optical rotations were measured with a Krüss P8000 polarimeter at the indicated concentration with the units of g/100 mL. Enantiomeric excesses were determined by chiral HPLC analysis using an Agilent 1200 LC instrument with a Daicel Chiralpak IB, IC, or ADH column.
The following compounds were prepared following procedures reported in the literature: 1a‒g [15 (link)], 2a‒o [34 (link)], and chiral organocatalysts [35 (link)–38 (link)].