The cost-effectiveness of drug synthesis depends on a number of factors, including the amount of waste produced. A team of researchers have now discovered a catalyst that achieves exceptionally high-precision addition of hydrogen to carbon-carbon bonds, improving targeted synthesis by avoiding convoluted multi-step processes, and reducing wasteful by-products. In the journal Angewandte Chemie, the authors herald the reaction as especially useful in the production of complex natural substances such as pheromones.