One-pot, direct incorporation of [11C]CO2 into carbamates.

Why beat about the bush? An operationally simple and mild reaction based on the direct fixation of (11)CO(2) with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) has been developed for the synthesis of (11)C-labeled carbamates at 75 degrees 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.