Rapid access to N-substituted diketopiperazines by one-pot Ugi-4CR/deprotection+activation/cyclization (UDAC).
The most efficient diversity generating approaches to heterocycles are combinations of a multicomponent (MCR) with a cyclization reaction, for example, by Ugi-deprotection-cylization (UDC) protocols. If the desired post-Ugi reaction requires more than one deprotection, for example of two initially protected Ugi-reactive groups, or if it requires additional activation, for example, by an Ugi-activation-cyclization (UAC), either the isolation of intermediates or a sequential process or both become necessary. A recently introduced convertible isonitrile reagent allows a mild and chemoselective in situ post-Ugi activation of the isonitrile-born carboxylate with simultaneous deprotection of the nucleophilic amine, that is, liberation and activation of two Ugi-reactive groups, if desired also under subsequent lactam formation. This is exemplified by the synthesis of peptide-peptoid diketopiperazines.
Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120, Halle (Saale), Germany.
Cristiano R B
CR
Rhoden
Daniel G
DG
Rivera
Oliver
O
Kreye
Anne K
AK
Bauer
Bernhard
B
Westermann
Ludger A
LA
Wessjohann
D020650:Combinatorial Chemistry Techniques / Q000379:methods; D003500:Cyclization; D054659:Diketopiperazines / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
D054659:Diketopiperazines