Recent developments in carbonylation chemistry using [13 C]CO, [11 C]CO, and [14 C]CO.

Carbon monoxide represents the most important C1-building block for the chemical industry, both for the production of bulk and fine chemicals, but also for synthetic fuels. Yet its toxicity and subsequently its cautious handling have limited its applications in medicinal chemistry research and in particular for the synthesis of pharmaceutically relevant molecules. Recent years have nevertheless witnessed a considerable headway on the development of carbon monoxide surrogates and reactor systems, which provide an ideal setting for performing carbonylation chemistry with stoichiometric and substoichiometric carbon monoxide. Such setups are particularly ideal for the introduction of isotope labels such as carbon-11, carbon-13, and carbon-14 into bioactive compounds. This review summarizes this growing field and examines the large number of carbonylation reactions that can be exploited for the introduction of a carbon isotope.