This report describes the site-selective α-functionalization of sulfonylamide derivatives through the in-situ generation of imine intermediates. The N-F sulfonylamides, which could facilitate the elimination to generate imines, are coupled with TBACN to efficiently and mildly afford α-amino cyanides. Comparing with Strecker reaction, this transformation offers a complementary strategy to efficiently construct α-amino cyanides from direct α C-H functionalization of sulfonylamindes. The reaction is also characterized by broad substrate scope and flash chromatography column free workup. More importantly, the new two-electron pathway to generate imines through manipulation of the leaving group allows us to achieve excellent α site-selectivity.
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http://dx.doi.org/10.1002/chem.202100902 | DOI Listing |
Catal Sci Technol
December 2024
Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern Freiestrasse 3 3012 Bern Switzerland
Even though α-arylation of ketones is attractive for direct C-H functionalization of organic substrates, the method largely relies on phosphine-ligated palladium complexes. Only recently, efforts have focused on developing nitrogen-based ligands as a more sustainable alternative to phosphines, with pyridine-functionalized pyridinium amidate (pyr-PYA) ,'-bidentate ligands displaying good selectivity and activity. Here, we report on a second generation set of catalyst precursors that feature a 5-membered N-heterocycle instead of a pyridine as chelating unit of the PYA ligand to provide less steric congestion for the rate-limiting transmetalation of the enolate.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata, 700106, India.
The conversion of solar energy into chemical energy or high-value chemicals has attracted considerable research interest in the context of the global energy crisis. Hydrogen peroxide (HO) is a versatile and powerful oxidizing agent widely used in chemical synthesis and medical disinfection. HO also serves as a clean energy source in fuel cells, generating electricity with zero-carbon emissions.
View Article and Find Full Text PDFNat Chem
January 2025
Key Laboratory of Advanced Marine Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China.
sp-carbon-linked covalent organic frameworks (spc-COFs) are crystalline porous polymers with repeat organic units linked by sp carbons, and have attracted increasing interest due to their robust skeleton and tunable semiconducting properties. Single-crystalline spc-COFs with well-defined structures can represent an ideal platform for investigating fundamental physics properties and device performance. However, the robust olefin bonds inhibit the reversible-reaction-based crystal self-correction, thus yielding polycrystalline or amorphous polymers.
View Article and Find Full Text PDFChemistry
January 2025
Zelinsky Institute of Organic Chemistry of the Russian Academy of Science, Laboratory for Studies of Homolytic Reactions, Leninsky prospekt 47, 119991, Moscow, RUSSIAN FEDERATION.
The electrochemically mediated cyanation/annulation process with in situ cyanide ion generation from NH4SCN and multi-step oxidative construction of CN-functionalized heterocycles from easily available α-amino esters and pyridine-2-carbaldehydes has been discovered. Depending on the nature of the α-amino ester, 1-cyano-imidazo[1,5-a]pyridine-3-carboxylates, 3-alkyl- and 3-aryl-imidazo[1,5-a]pyridines-1-carbonitriles, and the first reported 4-oxo-4H-pyrido[1,2-a]pyrazine-1-carbonitriles were obtained. The electrosynthesis is carried out in an undivided electrochemical cell under constant current conditions.
View Article and Find Full Text PDFChemistry
January 2025
Department of Molecular Chemistry, Materials and Catalysis, Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Place Louis Pasteur, 1 bte L4.01.06, 1348, Louvain-La-Neuve, Belgium.
We introduce mechanochemical deracemization (MCDR) as a novel strategy for obtaining enantiopure compounds. This study demonstrates the successful transposition of six archetypical deracemization reactions from a solvent-based to a solvent-minimized ball milling environment. The scope includes a ketone, isoindolinones, imines, an ester, and an inorganic compound, all of which deracemized successfully.
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