Ammonium Zincates as Catalysts for the Microwave-Enhanced Synthesis of Symmetric Piperazines by Regioselective Opening of Aziridines.
Chem Asian J
; : e202400688, 2024 Aug 13.
Article
en En
| MEDLINE
| ID: mdl-39136397
ABSTRACT
2,5-disubstituted N,N'-alkylpiperazines represent an interesting target in organic synthesis both for pharmaceutical or agrochemical applications and as a promising class of ligands in coordination chemistry. We report here a microwave-enhanced synthesis of these compounds starting from non-activated N-alkyl aziridines in the presence of catalytic amounts of simple ammonium metallates. A remarkable TOF of 2787.9â
h-1 has been observed in the case of [TBA]2[ZnI4] as the catalyst (catalyst loading 0.1â
mol %) and with an almost complete selectivity (up to 97 %) in favor of both diastereoisomers (meso and chiral form) of the target 2,5-disubstituted piperazines, obtained in 1 1 ratio. The two isomers are easily separated, because the meso form precipitates in pure from the reaction crude. A stereochemical investigation and the unprecedented isolation of 2,6-disubstituted N,N'-alkylpiperazines allowed us to shed light on the reaction mechanism.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Chem Asian J
Año:
2024
Tipo del documento:
Article
País de afiliación:
Italia
Pais de publicación:
Alemania