Cyrene as a bio-based solvent for HATU mediated amide coupling

Amide bonds are one of the underpinning linkages in all living systems and are fundamental within drug discovery. Current methods towards their synthesis frequently rely on the use of dipolar aprotic solvents; however, due to increasingly stringent regulations and growing societal pressures, safe and more sustainable alternatives are highly sought after. Herein, we evaluate the application of the bio-based solvent Cyrene™ in the HATU mediated synthesis of amides and peptides. We found that Cyrene functioned as a competent replacement for DMF in the synthesis of a series of lead-like compounds and dipeptides (25 examples, 63-100%).