Design and Synthesis of New Protease-Triggered CO-Releasing Peptide–Metal-Complex Conjugates

Abstract

Aiming at the development of novel protease-triggered CO-releasing molecules (PT-CORMs) we designed a series of oxycyclohexadiene-Fe(CO)3 complexes, which are connected through a self-immolative linker with a plasmin-specifying peptide unit. The challenging synthesis of these compounds was elaborated employing a combination of solid-phase peptide synthesis and solution chemical synthesis. Late-stage attachment of the organometallic unit and Pd-catalyzed cleavage of an alloc-protected lysine side chain afforded the target compounds in good yields and high purity.