<i>p</i>‐Nitrobenzyloxycarbonyl (pNZ) as a Temporary <i>N</i><i>^α</i>‐Protecting Group in Orthogonal Solid‐Phase Peptide Synthesis – Avoiding Diketopiperazine and Aspartimide Formation

Abstract

Abstract p‐ Nitrobenzyloxycarbonyl (pNZ) was used as a temporary protecting group for α‐amino functionalities in solid‐phase peptide synthesis. The corresponding derivatives are readily synthesized solids that perform well on solid phase. The pNZ moiety is orthogonal with the most common protecting groups used in peptide chemistry, and is removed under neutral conditions in the presence of catalytic amounts of acid. The use of pNZ derivatives in conjunction with Fmoc chemistry circumvents typical side reactions associated with the use of piperidine, such as DKP and aspartimide formation. The flexibility of pNZ can be exploited for the preparation of libraries of small organic molecules. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2005)