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Detail publikace

Autor: Vaňková, B.; Brulíková, L.; Wu, B.; Krchňák, V.
Název práce v češtině: Syntéza piperazinonů, piperazinů, tetrahydropyrazinů a dihydropyrazinů z acyklických intermediátů přes N-alkyl a N-acyliminiové soli
Název práce v angličtině: Synthesis of Piperazinones, Piperazines, Tetrahydropyrazines, and Dihydropyrazinones from Polymer-Supported Acyclic Intermediates via N-Alkyl- and N-Acyliminiums
Studentská publikace: ne
Klíčová slova v češtině: Piperazinony, Cyklizace, Piperaziny, Solid-phase syntéza, Iminiové soli, Heterocykly
Klíčová slova v angličtině: Piperazinones, Cyclization, Piperazines, Solid-phase synthesis, Iminiums, Heterocycles
Abstrakt česky: Trisubstituted piperazinones, piperazines, tetrahydropyrazines, and dihydropyrazinones were prepared in a one-step procedure from easily accessible polymer-supported acyclic precursors containing either a masked aldehyde or ketone group. Acid-mediated unmasking of the aldehyde triggered cyclic iminium formation followed by reduction with triethylsilane present in the cleavage cocktail. The effect of the substituent at the iminium-forming nitrogen was evaluated: whereas complete conversion to the target compounds was observed with N-alkyl, aryl, and phenylsulfonamido derivatives, the N-acyl compound suffered from a partial reduction of the aldehyde to an alcohol. Similarly, ketones readily provided cyclic iminiums with N-alkyl compounds, whereas their cyclization with N-acyl precursors proceeded unwillingly. Interestingly, cleavage of the resin-bound acyclic precursor at 60 °C in the presence of triethylsilane resulted in the decomposition of the amide bond and formation of a lactone. An analogous synthetic route was also successfully used for the preparation of piperazines and tested as an alternative route for the synthesis of diazepanones.
Abstrakt anglicky: Trisubstituted piperazinones, piperazines, tetrahydropyrazines, and dihydropyrazinones were prepared in a one-step procedure from easily accessible polymer-supported acyclic precursors containing either a masked aldehyde or ketone group. Acid-mediated unmasking of the aldehyde triggered cyclic iminium formation followed by reduction with triethylsilane present in the cleavage cocktail. The effect of the substituent at the iminium-forming nitrogen was evaluated: whereas complete conversion to the target compounds was observed with N-alkyl, aryl, and phenylsulfonamido derivatives, the N-acyl compound suffered from a partial reduction of the aldehyde to an alcohol. Similarly, ketones readily provided cyclic iminiums with N-alkyl compounds, whereas their cyclization with N-acyl precursors proceeded unwillingly. Interestingly, cleavage of the resin-bound acyclic precursor at 60 °C in the presence of triethylsilane resulted in the decomposition of the amide bond and formation of a lactone. An analogous synthetic route was also successfully used for the preparation of piperazines and tested as an alternative route for the synthesis of diazepanones.
Jazyk v originále: anglictina
Název časopisu: Eur. J. Org. Chem.
Rok: 2012
Svazek (ročník): 2012
Číslo časopisu v rámci uvedeného svazku: 26
Strana od-do: 5075-5084

Q1: ne

ISSN časopisu: 0009-4374 (print)
Vydavatel: Elsevier
Způsob financování: ME09057, CZ.1.07/2.3.00/20.0009