The regio- and enantio-selective, intermolecular vicinal fluoroamination of α-trifluoromethyl styrenes has been achieved by enantioselective I /I catalysis. Leveraging C -symmetric resorcinol-based aryl iodide catalysts, it has been possible to intercept the transient iodonium intermediate using simple nitriles, which function as both the solvent and nucleophile. In situ Ritter reaction provides direct access to the corresponding amides (up to 89 % yield, e.r. 93 : 7). This main group catalysis paradigm inverts the intrinsic regioselectivity of the uncatalyzed process, thereby providing facile access to tertiary, benzylic stereocenters bearing both CF and F groups. Privileged phenethylamine pharmacophores can be generated in which there is complete local partial charge inversion (CF /F versus CH /H ). Crystallographic analyses of representative β-fluoroamide products reveal highly pre-organized conformations that manifest the stereoelectronic gauche effect.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9400885 | PMC |
http://dx.doi.org/10.1002/anie.202205508 | DOI Listing |
Angew Chem Int Ed Engl
March 2025
Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Shenzhen Grubbs Institute, Guangming Advanced Research Institute, Department of Chemistry, and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, P. R. China.
Enantioenriched α-aminoketones serve as important substructures in life science and precursors for the synthesis of diverse value-added targets in organic and biochemistry. However, direct access to enantioenriched α-aminoketones from simple and readily available starting materials remains a formidable challenge. Herein, we report an unprecedented nickel-catalyzed asymmetric cross-coupling protocol for the synthesis of enantioenriched α-N-heteroaryl ketones from alkenes and enamines in the presence of a carbon monoxide surrogate.
View Article and Find Full Text PDFJ Phys Chem A
March 2025
School of Chemical Engineering, University of Science and Technology Liaoning, Qianshan Road 185, Anshan 114051, China.
A theoretical study on the mechanism, regioselectivity, and enantioselectivity of NHC-catalyzed dearomatizing annulation of benzoxazoles with enals has been conducted using density functional theory calculations. Our calculated results indicate that the favored mechanism occurs through eight reaction steps: initial binding of the NHC to enals, followed by formation of the Breslow intermediate via proton transfer. Subsequent oxidation generates the α,β-unsaturated acylazolium intermediate, which can undergo Michael addition with benzoxazoles.
View Article and Find Full Text PDFNat Commun
March 2025
School of Chemistry and Chemical Engineering, Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Shanghai Jiao Tong University, 200240, Shanghai, P. R. China.
A highly enantioselective electrophilic selenylation/semipinacol rearrangement of allenols has been developed, which is enabled by the cooperative catalysis of a chiral sulfide and an achiral sulfonic acid. The designed and synthesized chiral sulfide catalyst and selenylating reagent play a crucial role in enhancing both enantioselectivity and reactivity. This approach exhibits excellent regio-, chemo-, and enantioselectivity, providing access to diverse enantioenriched cyclopentanones featuring an arylselenovinyl-substituted quaternary carbon stereocenter.
View Article and Find Full Text PDFChem Commun (Camb)
February 2025
Key Laboratory of Phytochemistry and Natural Medicines, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
An enantioselective preparation of vinyl, alkyl-substituted chiral α-stereogenic acrylates is reported using two consecutive steps of Ir-catalysed allylic alkylation of aliphatic allylic acetates with phosphonates and Horner-Wadsworth-Emmons olefination. Unlike commonly utilised iridium-phosphoramidite catalysts, Krische's catalyst was uniquely effective in promoting highly regio- and enantioselective reactions of alkyl-substituted allylic substrates, thus constituting a significant alternative to the known protocol.
View Article and Find Full Text PDFJ Am Chem Soc
March 2025
Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
The direct functionalization of alkyne triple bonds using a radical strategy provides an efficient platform for creating a wide range of substituted alkenes. However, developing a multicomponent enantioselective radical reaction using feedstock alkynes to forge all-carbon quaternary stereocenters─while addressing challenges related to compatibility, selectivity, and efficiency─remains relatively rare. Here we report an enantioselective electrochemical nickel-catalyzed three-component cross-coupling of readily available terminal alkynes, diverse racemic alkyl radical precursors, and group transfer reagents (such as (TMS)Si-H, RSe-SeR, RTe-TeR, and CHI), achieving excellent regio-, stereo-, and enantioselectivities (more than 70 examples, up to 95% ee).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!