Sps 800

All synthetic and kinetic experimental procedures
were performed
under inert conditions using standard Schlenk techniques or inside
an mBraun inert atmosphere glovebox containing an atmosphere of purified
nitrogen. Dry solvents were dispensed from an mBraun SPS-800 solvent
purification system and degassed for 20 min before use by purging
with dry N₂.
Caution! Hydrofluoric
acid (HF) was identified
as a product of the reactions listed above. HF is a highly corrosive
inorganic acid. Therefore, reactions with the potential for formation
of HF must be handled with extreme caution. HF can penetrate the skin
extremely easily and decalcifies bones, leading to tissue necrosis,
which may result in amputation and death. Solutions as weak as 1%
can still rapidly permeate the skin and severely damage underlying
tissues. The maximum concentration of HF that can be formed throughout
this work was capped at 0.017%. Furthermore, all the locally defined
protective measures for working with metal-fluorides and HF were followed
for all experiments.

Ferulic acid, 1 M diisobutyl aluminum hydride in dichloromethane, benzyl bromide, laccase from Trametes versicolor (776 U/g), piperazine, and sodium hydride were purchased from Sigma-Aldrich and used as received. Acetovanillone, sodium borohydride, pyridine, and diethylcarbonate were purchased from TCI and used as received. Palladium on carbon and anhydrous magnesium sulfate were purchased from Acros Organics and used as received. Deuterated solvents were purchased from Euriso-top. Other reagents, salts, and solvents were purchased from VWR.
DMF was dried using mBraun SPS 800. Evaporations were conducted under reduced pressure (Vario Vacuubrand pump) on Buchi R300. Flash chromatographies were performed on a Puriflash 4100 (Interchim) equipped with and pre-packed INTERCHIM PF-30SI-HP (30 μm silica gel) columns. IR analyses were performed on Cary 630 FTIR (Agilent). NMR analyses were recorded on a Bruker Fourier 300. ¹H NMR spectra of samples were measured on a 300 MHz apparatus, chemicals shifts were reported in parts per million relative to solvent residual peak (CDCl₃ δ = 7.26 ppm; DMSO-d₆ δ = 2.50 ppm). ¹³C NMR spectra of samples were recorded at 75 MHz and calibrated on solvent peak (CDCl₃ δ = 77.16 ppm; DMSO-d₆ δ = 39.52 ppm).

All chemicals were purchased from Sigma-Aldrich, Acros Chemicals, Fluorochem or Alfa Aesar and used without further purification unless otherwise stated. Anhydrous acetonitrile was obtained from a MBraun SPS800 solvent purification system unless otherwise stated. Flash column chromatography was performed using Biotage Flash Purification system. ¹H NMR and ¹³C NMR spectra were measured on a Bruker Avance 500 NMR spectrometer and Bruker Avance DPX400 spectrometer. ¹H NMR and ¹³C NMR spectra are reported as chemical shifts in ppm downfield from TMS and J values are given in Hertz. ³¹P NMR spectra were recorded on Bruker Avance DPX400 spectrometer or Bruker Avance 500 NMR spectrometer and are reported in chemical shifts downfield from 85% H₃PO₄. Reverse phase HPLC was performed on a system comprising of a Dionex P680 pump and a Dionex UVD170U detector unit.

Chemicals were purchased from Sigma–Aldrich, VWR, ABCR, and Fisher Scientific and were used as received. THF and Et₂O were distilled from sodium/benzophenone. CH₂Cl₂ was distilled from calcium hydride or freshly purified using MBraun SPS-800 drying columns. All reactions were performed under an inert atmosphere of N₂ or Ar using standard Schlenk techniques. Column chromatography was performed using Merck silica gel Si-60 Å (35–70 or 0.063–0.200 mm) or on basic alumina (Aldrich type 5016A, 150 mesh, 58 Å).