Creating a Defined Chirality in Amino Acids and Cyclic Dipeptides by Photochemical Deracemization

Abstract: 2,5‐Diketopiperazines are cyclic dipeptides displaying a wide range of applications. Their enantioselective preparation has now been found possible from the respective racemates by a photochemical deracemization (53 examples, 74 % to quantitative yield, 71–99 % ee). A chiral benzophenone catalyst in concert with irradiation at λ=366 nm enables to establish the configuration at the stereogenic carbon atom C6 at will. If other stereogenic centers are present in the diketopiperazines they remain unaffected and a stereochemical editing is possible at a single position. Consecutive reactions, including the conversion into N‐aryl or N‐alkyl amino acids or the reduction to piperazines, occur without compromising the newly created stereogenic center. Transient absorption spectroscopy revealed that the benzophenone catalyst processes one enantiomer of the 2,5‐diketopiperazines preferentially and enables a reversible hydrogen atom transfer that is responsible for the deracemization process. The remarkably long lifetime of the protonated ketyl radical implies a yet unprecedented mode of action.

Standort
Deutsche Nationalbibliothek Frankfurt am Main
Umfang
Online-Ressource
Sprache
Englisch

Erschienen in
Creating a Defined Chirality in Amino Acids and Cyclic Dipeptides by Photochemical Deracemization ; day:18 ; month:10 ; year:2023 ; extent:11
Angewandte Chemie ; (18.10.2023) (gesamt 11)

Urheber
Großkopf, Johannes
Plaza, Manuel
Kutta, Roger Jan
Nuernberger, Patrick
Bach, Thorsten

DOI
10.1002/ange.202313606
URN
urn:nbn:de:101:1-2023101915061453494953
Rechteinformation
Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
Letzte Aktualisierung
14.08.2025, 10:58 MESZ

Datenpartner

Dieses Objekt wird bereitgestellt von:
Deutsche Nationalbibliothek. Bei Fragen zum Objekt wenden Sie sich bitte an den Datenpartner.

Beteiligte

Ähnliche Objekte (12)