Hydrogenolysis of halogen derivatives is an important method for the preparation of specifically deuterated or tritiated compounds I ,2. In view of the well-known selectivity3,4 of homogeneously catalysed hydrogenation reactions, compared to the heterogeneous catalysis, we attempted to apply the homogeneous hydrogena- tion to reductive dehalogenation. The chosen substrate was 5-iodouracil, to make the results comparable with the thoroughly studied ...