One-step exchange-labelling of pyridines and other N-heteroaromatics using deuterium gas: catalysis by heterogeneous rhodium and ruthenium catalysts

A wide range of pyridines and other nitrogen heteroaromatics can be labelled with deuterium at room temperature and pressure by isotopic exchange with deuterium gas in THF in the presence of rhodium black, ruthenium black or 5% rhodium on alumina. The labelling is rapid, isotope efficient and applicable to both electron-rich and electron-poor substrates. In a few cases, a degree of reduction accompanies the exchange.