Spherical silica gel 60n

All reagents were purchased from commercial
sources and used without further purification. Dry THF was also purchased
from a commercial source and used as received. Gravity column chromatography
was performed using Kanto Chemical Co. spherical silica gel 60N with
a particle size of 63–210 μm. ¹H, ¹³C, and ¹⁹F NMR spectra were recorded on Bruker AVANCE
III 400 spectrometer (400 MHz, 100 MHz, and 376 MHz, respectively).
All chemical shifts (δ) are reported in ppm and coupling constants
(J) are in Hz. The ¹H and ¹³C NMR chemical shifts are relative to tetramethylsilane; the resonance
of the residual protons of chloroform was used as an internal standard
for ¹H (δ 7.26 ppm) and all-d solvent peaks for ¹³C (δ 77.0 ppm).^{18 (link)} The assignments
of the ¹³C NMR were performed by DEPT experiments. ¹⁹F NMR chemical shifts are relative to hexafluorobenzene in
CDCl₃ at δ = -163.0 ppm (external reference).^{19 (link)} High-resolution mass spectra were recorded on
a JEOL JMS-700N spectrometer. Melting points were recorded on an Anatec
Yanaco MP-J3 and were uncorrected. Geometrical optimization was carried
out at the B3LYP/6-31g(d,p) level of theory implemented on the Gaussian
09 package.¹⁶

All reagents and organic solvents were purchased from Kanto Chemical, Kishida Chemical, Nacalai Tesque, Sigma-Aldrich, TCI, Wako Pure Chemical Industries, and Yoneyama Yakuhin Kogyo, and were used without further purification. Distilled water was obtained from an EYELA SA-2100E automatic water distillation apparatus. Thin-layer chromatography (TLC) was performed using a Merck TLC Silica 60 F254. Column chromatography was carried out with Kanto Chemical spherical silica gel 60 N (neutral, 63–210 μm).