14Carbon monoxide made simple - novel approach to the generation, utilization, and scrubbing of 14carbon monoxide

A new method is reported for the efficient generation of 14CO that can be applied in transition metal-catalyzed carbonylation reactions. 14CO is produced by palladium-catalyzed decarbonylation of the stable acid chloride, 14COgen. When combined in a two-chamber system, the produced 14CO is incorporated into the target molecule with high efficiency. As the carbonylation chemistry is performed under mild conditions, this allows the 14C isotope to enter the synthesis into an advanced stage intermediate. The presented work includes two aminocarbonylations, one amidocarbonylation, and one carbonylative SuzukiMiyaura coupling, all installing the 14C isotope in the final step of the synthesis. Finally, the identification of a highly efficient scrubber for the safe trapping and removal of any leftover 14CO is also disclosed.