Hooker, Jacob M., Achim T. Reibel, Sidney M. Hill, Michael J. Schueller, and Joanna S. Fowler. 2009. “One-Pot, Direct Incorporation of [11C]CO2into Carbamates.” Angewandte Chemie International Edition 48 (19) (April 27): 3482–3485. doi:10.1002/anie.200900112.
Why beat about the bush? An operationally simple and mild reaction based on the direct fixation of 11CO2 with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) has been developed for the synthesis of 11C-labeled carbamates at 75 °C within 10 minutes in radiochemical yields above 70 % (see scheme). This strategy should be immediately useful for the construction of new radiotracers for positron emission tomography and other applications.