A stable RGD-conjugated triarylmethyl (TAM) radical 3 has been synthesized in a straightforward three-step sequence. CT-03 ‘the Finland trityl’ which is a very popular contrast agent for electron paramagnetic resonance imaging has been covalently bound to the NH2-ending of a pentapeptide commonly used to target integrins and confers tissue selectivity. Moreover, this new TAM radical is stable and sensitive to molecular oxygen.
Driesschaert, B., Levêque, P., Gallez, B., & Marchand-Brynaert, J. (2013). RGD-conjugated triarylmethyl radical as probe for electron paramagnetic imaging. Tetrahedron Letters, 54(44), 5924-5926. https://doi.org/10.1016/j.tetlet.2013.08.120 (Original work published 2013)