A facile method has been developed for the synthesis of chiral piperazines through Ir-catalyzed hydrogenation of pyrazines activated by alkyl halides, giving a wide range of chiral piperazines including 3-substituted as well as 2,3- and 3,5-disubstituted ones with up to 96% ee. The high enantioselectivity, easy scalability, and concise drug synthesis demonstrate the practical utility.
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http://dx.doi.org/10.1021/acs.orglett.6b01190 | DOI Listing |
Chem Asian J
November 2024
Department of Chemistry, Università degli Studi di Milano and CNR-SCITEC, Via Golgi 19, 20133, Milano, Italy.
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.
View Article and Find Full Text PDFEur J Med Chem
October 2024
Engineering Center of Catalysis and Synthesis for Chiral Molecules, Department of Chemistry, Fudan University, Shanghai, 200433, China; Shanghai Engineering Center of Industrial Asymmetric Catalysis for Chiral Drugs, Shanghai, 200433, China. Electronic address:
Starting from our previously reported nonnucleoside reverse transcriptase inhibitor (NNRTI, 3), continuous efforts were made to enhance its potency and safety through a structure-based drug design strategy. This led to the discovery of a series of novel piperidine-biphenyl-diarylpyrimidines (DAPYs). Compound 10p, the most active compound in this series, exhibited an EC value of 6 nM against wide-type HIV-1 strain, which was approximately 560-fold more potent than the initial compound 3 (EC = 3.
View Article and Find Full Text PDFChirality
May 2024
Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada.
The separation of chiral drugs continues to pose a significant challenge. However, in recent years, the emergence of membrane-based chiral separation has shown promising effectiveness due to its environmentally friendly, energy-efficient, and cost-effective characteristics. In this study, we prepared chiral composite membrane via interfacial polymerization (IP), utilizing β-cyclodextrin (β-CD) and piperazine (PIP) as mixed monomers in the aqueous phase.
View Article and Find Full Text PDFJ Am Chem Soc
May 2024
Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.
Despite much progress in the area of dearomatization, the enantioselective dearomatization of heterocycles is limited to those with a single heteroatom. Here we report a highly enantioselective copper-catalyzed dearomatization of pyrazine, a diazine, leading to chiral C-substituted piperazines. When exposed to a chloroformate and an alkyne in the presence of a catalyst derived from a copper salt and the chiral ligand StackPhos, pyrazine is readily dearomatized to provide a 2,3-disubstituted dihydropyrazine as single diastereomer in high enantiomeric excess.
View Article and Find Full Text PDFTalanta
July 2024
Department of Analytical Chemistry and Pollutants, Shahid Beheshti University, Tehran, Iran. Electronic address:
The present study investigates the use of dextrins (maltodextrin, β-cyclodextrin, and hydroxypropyl-β-cyclodextrin) to improve the efficiency of the agarose-based gel electromembrane extraction technique for extracting chiral basic drugs (citalopram, hydroxyzine, and cetirizine). Additionally, it examines the enantioselectivity of the extraction process for these drugs. To achieve these, dextrins were incorporated into either the sample solution, the membrane, or the acceptor solution, and then the extraction procedure was performed.
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