Synthesis of 11C-radiopharmaceuticals using direct fixation of [11C]carbon dioxide and [11C]carbon monoxide

A brief review describes syntheses of various 11C-radiopharmaceuticals via direct fixation of [11C]carbon dioxide and [11C]carbon monoxide as radiolabelled precursors into bio-organic molecules. Using [11C]carbon dioxide, the syntheses of [11C]carboxylic acids and their derivatives and [11C]amino acids via organometallic carbonion intermediates and syntheses of [11C]secondary amines via reductive carboxylation are described. Biosynthetic fixation of [11C]CO2, enzymatic fixation and fixation via plants/algae are also discussed. Using [11C]carbon monoxide, the syntheses of labelled piperidines, aldehydes and butanol are described. (U.K.)