A variety of complex compounds have been labeled with tritium gas by cataly
tic exchange in the presence of catalyst precursors [(cod)Ir(dppe)]BF4 or [
(cod)Ir(py)(PCy3)]BF4. In most cases, predictable regioselectivity and high
specific activities are achieved. These results are compared in some cases
to the results of labeling related compounds with [(cod)Ir(PPh3)(2)]BF4. P
rereduction of the catalyst precursors in situ with hydrogen allows the use
of smaller quantities of tritium gas and reduces the amount of radioactive
waste. Two or more compounds can be labeled simultaneously as mixtures the
n separated in the HPLC purification step to increase compound throughput.