Carbon monoxide is used in many chemical syntheses. It is a colorless, odorless gas that is highly toxic. Exposure to CO is hard to detect until the late stages so it must be handled with extreme caution. Troels Skrydstrup and co-workers, Aarhus University, Denmark, have developed a harmless powder, which when treated with a catalyst can release CO for use in organic reactions.

The team used a sealed two-chamber system with a CO-producing chamber and a CO-consuming chamber. A stable and solid acid chloride derivative was decarbonylated by a palladium catalyst. The resultant CO then diffused into the CO-consuming chamber where a range of carbonylation reactions were performed leading to several pharmaceutically relevant compounds.

This technique will be of high value for synthetic chemists, not only as a new source of a safe and storable CO gas, but also because of its ease in handling and straightforward use in CO related chemistry, including isotope labeling studies.

• Ex Situ Generation of Stoichiometric and Substoichiometric ¹²CO and ¹³CO and Its Efficient Incorporation in Palladium Catalyzed Aminocarbonylations
  P. Hermange, A. T. Lindhardt, R. H. Taaning, K. Bjerglund, D. Lupp, T. Skrydstrup,
  J. Am. Chem. Soc. 2011.
  DOI: 10.1021/ja200818w