Segmental Deuterium Labeling of Alkyl Chains by Nickel–Mediated Desulfurization

Publication Summary

Originally published in the Asian Journal of Organic Chemistry, this study describes a general method for preparing segmentally deuterium-labeled alkyl chains using nickel boride-mediated reductive desulfurization of substituted thiophenes. The approach provides access to highly deuterated compounds for applications in mass spectrometry, neutron scattering, and biochemical research, while relying only on commercially available starting materials and simple purification methods such as recrystallization or distillation.

To evaluate deuterium retention during the desulfurization process, the researchers employed molecular rotational resonance (MRR) spectroscopy to measure the degree and location of isotope scrambling. The analysis revealed hydrogen exchange during thiophene saturation and reagent-dependent isotope scrambling at benzylic positions, providing new insight into the reaction mechanism while confirming the method's utility for the synthesis of segmentally deuterated compounds and mass spectrometry standards.