Organocatalytic α-oxygenation of chiral aldehydes with photochemically generated singlet oxygen allows synthesizing chiral 3-substituted 1,2-diols. Stereochemical results indicate that the reaction in the presence of diarylprolinol silyl ethers is highly diastereoselective and that the configuration of a newly created stereocenter at the α-position depends predominantly on the catalyst structure. The absolute configuration of chiral 1,2-diols has been unambiguously established based on electronic circular dichroism (ECD) and TD-DFT methods.
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http://dx.doi.org/10.3762/bjoc.15.205 | DOI Listing |
J Am Chem Soc
January 2025
Key Laboratory of Applied Chemistry of Chongqing Municipality and Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
Achieving catalytic asymmetric functionalization of methylenecyclopropanes (MCPs) by selective C-C bond cleavage is a notable challenge due to the intricate reaction partners involved. In this work, we report that chiral aldehyde/palladium combined catalysis enables the asymmetric functionalization of MCPs with NH-unprotected amino acid esters. This reaction proceeds through a regiospecific branched ring-opening mechanism, resulting in optically active α,α-disubstituted α-amino acid esters bearing nonconjugated terminal alkene units.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
IISER Kolkata: Indian Institute of Science Education and Research Kolkata, Department of Chemical Sciences, Mohanpur, 741246, Nadia, INDIA.
Chiral allyl amines are important structural components in natural products, pharmaceuticals, and chiral catalysts. Herein, we report a cobalt-catalyzed enantioselective reductive coupling of imines with internal alkynes to synthesize chiral allyl amines. The reaction is catalyzed by a cobalt complex derived from commercially available bisphosphine ligand utilizing zinc as the electron donor.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States.
Highly stereo- and enantioselective synthesis of δ-alkyl-substituted ()-homoallylic alcohols via asymmetric allylation is developed. In the presence of a chiral phosphoric acid catalyst, allylation of aldehydes with α-substituted allylboronates provides δ-alkyl-substituted homoallylic alcohols with excellent ()-selectivities and enantioselectivities.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States.
Highly fluorinated naphthyl aldehyde and binaphthyl aldehyde ()- were designed and synthesized for fluorous-phase-based sensing. Greatly enhanced sensitivity and chemoselectivity in going from to ()- in the fluorescent detection of cysteine has been discovered. This is attributed to the increased structural rigidity of the axially chiral binaphthyl unit in ()- upon reaction with cysteine to form the corresponding thiazolidine product.
View Article and Find Full Text PDFChirality
January 2025
Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China.
A chiral porous organic polymer (cPOP) was synthesized through nucleophilic substitution polymerization between dichloromaleimide and aromatic amine. This cPOP was used as a new chiral stationary phase (CSP) for gas chromatography (GC) chiral separation. In this work, we first used this cPOP as the CSP for gas chromatography to investigate its ability to separate racemic mixtures, including amino acid derivatives, chiral alcohols, aldehydes, alkanes, ketones, esters, and organic acids.
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