Work

Ammonium Zincates as Catalysts for the Microwave‐Enhanced Synthesis of Symmetric Piperazines by Regioselective Opening of Aziridines

Year: 2024

Type: article

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 2787.9 h−1 has been observed in the case of [TBA]2[ZnI4] as the catalyst (catalyst loading 0.1 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.

Source: Chemistry - An Asian Journal

DOI: 10.1002/asia.202400688

Authors: Matteo Alberti, Andrea Dariol, Nicola Panza, Giorgio Abbiati, Alessandro Caselli

Institution: University of Milan

Language: English

Topic: Synthesis and Catalytic Reactions

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,430

Funders: Università degli Studi di Milano, Papua New Guinea University of Technology