Optimization of carbon-11-carboxylate exchange of α-amino acids

Radiolabelled amino acids offer a broad spectrum of applications in clinical care and pharmaceutical development. Traditional methods of labelling are limited in their availability, requiring specialized equipment and reagents, and in their scope, addressing only select amino acids. We discovered a simple and efficient approach using aldehyde-catalysed carboxylate exchange to 11 C-amino acids. Seeking enrichment of the carbon-11 methodology and the preparation of radiotracers suitable for animal imaging, we explored further optimization and probe development. We detail herein method development, including evaluations of aldehyde catalysts, discovering optimal reaction conditions, and the production of enantiopure radiolabelled amino acids.