J 2015

A Simplified Protocol for Routine Chemoselective Syntheses of Piperazines Substituted In the 1-Position by an Electron Withdrawing Group

NĚMEČKOVÁ, Dana a Pavel PAZDERA

Základní údaje

Originální název

A Simplified Protocol for Routine Chemoselective Syntheses of Piperazines Substituted In the 1-Position by an Electron Withdrawing Group

Autoři

NĚMEČKOVÁ, Dana (203 Česká republika, domácí) a Pavel PAZDERA (203 Česká republika, garant, domácí)

Vydání

Current organic synthesis, Sharjah, Bentham Science Publ Ltd, 2015, 1570-1794

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10401 Organic chemistry

Stát vydavatele

Spojené arabské emiráty

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Impakt faktor

Impact factor: 2.050

Kód RIV

RIV/00216224:14310/15:00081732

Organizační jednotka

Přírodovědecká fakulta

UT WoS

000350751700007

Klíčová slova anglicky

1-monosubstituted piperazine; ionically-bound substrate; metal catalysis; piperazine; piperazine-1-ium cation; resin supported metal ion; solid phase synthesis

Štítky

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 5. 11. 2019 09:44, Mgr. Marie Šípková, DiS.

Anotace

V originále

We report a simplified protocol for the routine direct chemoselective preparation of various piperazines substituted in the 1-position by an electron withdrawing group. These syntheses are based on the reaction of piperazine-1-ium cation with different electrophilic reagents such as acyl chlorides, anhydrides, sulfonyl chlorides, carbamoyl chlorides, and nitrourea as well. Piperazine-1-ium cation was chosen because the reactions of piperazine with electrophilic reagents in different solvents at usual temperatures are not chemoselective and provide mixtures comprising 1-substituted, 1,4-disubstituted and unsubstituted piperazine as well. Simultaneously, the mono-protonation of piperazine is the simplest synthetic method for its protection/deprotection in comparison with the currently used mono-benzylation, mono-Boc-protection, etc. Computer modeling of acid-base equilibria for piperazine and model 1-acetylpiperazine was used as the basis for the prediction of reaction conditions suitable for the synthesis. It was found that for in situ generating of starting piperazine-1-ium cation from piperazine the application of acetic acid as reaction medium or the chemisorption of piperazine on weakly acidic cation-exchanger resin were highly acceptable in terms of both reaction times and yields. The using of resin supported piperazine-1-ium cation in reaction with carboxylic anhydrides or nitrourea is an example of the solid phase synthesis with ionically bonded substrate. Furthermore, syntheses in acetic acid medium were effectively catalyzed by Cu+, Cu2+ or Al3+ ions supported on weakly acidic cation-exchanger resin as well. Finally, it was observed that application of the solid support metal catalysis afforded target products in shortened reaction times and in 82-95% yields.

Návaznosti

2A-1TP1/090, projekt VaV
Název: Nové katalyzátory a činidla pro udržitelné zelené syntézy a kombinatoriální syntézy.
Investor: Ministerstvo průmyslu a obchodu ČR, Nové katalyzátory a činidla pro udržitelné zelené syntézy a kombinatoriální syntézy