Efficient C−H/C−D Exchange Reaction on the Alkyl Side Chain of Aromatic Compounds Using Heterogeneous Pd/C in D₂O

[reaction: see text] An efficient and extensive deuterium incorporation using heterogeneous Pd/C-D(2)O-H(2) system into many different types of unactivated C-H bond positions was developed. The present method provides a deuterium gas-free, totally catalytic, and post-synthetic deuterium labeling method in D(2)O media.