Automated Synthesis Protocol of Sequence-Defined Oligo-Urethane-Amides Using Thiolactone Chemistry

An automated, iterative protocol for the synthesis of multifunctional, sequence-defined oligo-urethane-amides using thiolactone chemistry is reported. Here, sequenced functionalization of the backbone is easily introduced using commercially available primary amines. The chemistry is carried out on solid phase using different supports for better optimization of the synthetic protocol and in order to demonstrate the versatility of the approach. This technique is very effective for iterative synthesis and solid-phase chemistry and enables the exploration of full automation of this approach using a robotic peptide synthesizer. As a result, this automated protocol allows for the synthesis of a sequence-defined nonamer of high purity.