General: all reagents were purchased from commercial sources and used without further purification. Column chromatography was performed with silica gel 60 (Merck 9385, 230–400 mesh) or aluminium oxide 90 (neutral, act. II–III, Merck 1097). NMR experimental : NMR spectra were acquired on a Bruker Avance-300 apparatus operating at 300.33 MHz for H and 75.52 MHz for C, equipped with a standard 4 m...

We show herein how the proton magnetization enhanced by dynamic nuclear polarization (DNP) can be efficiently transferred at moderate magic-angle spinning (MAS) frequencies to half-integer quadrupolar nuclei, S ≥ 3/2, using Dipolar-mediated Refocused Insensitive Nuclei Enhanced Polarization Transfer (D-RINEPT) technique, in which a symmetry-based recoupling scheme built from adiabatic inversion...