NMR Characterization and Purification Protocols

NMR spectra were recorded at room temperature
in 5 mm tubes on
a Bruker AC 400 MHz spectrometer (NMR facility, PCN-ICMG, Grenoble).
Chemical shifts (δ) are reported in parts per million (ppm)
from low to high field and referenced to residual nondeuterated solvent
relative to Me₄Si. Standard abbreviations for multiplicity
were used as follows: s = singlet; d = doublet; t = triplet; m = multiplet.
High-resolution mass spectrometry (HRMS) was carried out on a Bruker
UHR-Q-TOF MaXis-ETD (time of flight) mass spectrometer using electrospray
ionization (ESI) in Institut de Chimie Organique et Analytique (CBM-ICOA)
in Orleans (France). Reversed-phase HPLC was performed with a μ-bondapak-C18
analytical column (Waters Corporation, Milford, MA). A Waters chromatographic
system was used, with two M-510 pumps and a photodiode array detector
Waters 996 using Millenium 32 software. A linear gradient from 0 to
100% methanol in H₂O pH 2.5 (phosphoric acid), 2 mL/min
flow rate, was used.
N-(Prop-2-yn-1-yl)prop-2-ynamide 2 was prepared by biocatalyzed reaction as reported by us.^{20 (link)}para-Nitrophenyl propiolate 5,^{33 (link)}para-nitrophenyl
isonicotinate 13,^{22 (link)} NH₂EG-Biotine·TFA 21,^{34 (link)} and dansyl and tosyl sulfonamides 21a,b were prepared following reported procedures.^{19 (link)} Streptavidin-agarose was purchased from Thermo Scientific
Pierce (Waltham, MA).