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.
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http://dx.doi.org/10.1039/d5cc00072f | DOI Listing |
Chem 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 PDFChem Sci
January 2025
Department of Chemistry and Chemical Biology, Stevens Institute of Technology Hoboken NJ 07307 USA
Allylic diboronates are highly valuable reagents in organic synthesis. Existing methods predominantly yield alkyl-substituted allylic diboronates, while the incorporation of electrophilic carbonyl groups conjugated to these allylic systems remains unknown. We present a strain-release promoted cycloaddition-based strategy that enabled access to unprecedented carbonyl conjugated secondary allylic diborons.
View Article and Find Full Text PDFChemistry
February 2025
Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Translational Research Hub, Maindy Road, Cathays, Cardiff, Cymru/Wales, CF24 4HQ, UK.
Precise control of selective alkene functionalization is a continuing challenge in the chemical community. In this study, we develop a substitution-controlled regiodivergent thioetherification of di- or trisubstituted alkenes using 10 mol % tris(pentafluorophenyl)borane [B(CF)] as a catalyst and N-thiosuccinimide as a sulfenylating reagent. This metal-free borane catalyzed C-S bond forming method is utilized for a Csp-H sulfenylation reaction to synthesize an array of diphenylvinylsulfide derivatives with good to excellent yields (25 examples, up to 91 % yield).
View Article and Find Full Text PDFChemistry
July 2024
Fakultät für Chemie, Universität Duisburg-Essen, Universitätsstr. 7, D, 45117, Essen, Germany.
Green chemistry strives for sustainability at the molecular level and is gaining increasing relevance in the development of chemical reactions. The haloalkynylation reaction is a highly atom-economical C-C coupling reaction that was previously only achieved using transition metal catalysts. It enables the introduction of an alkyne unit and a halogen atom into the target molecule.
View Article and Find Full Text PDFInt J Biol Macromol
April 2024
State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address:
Diclofenac sodium (DCF) was reported as an important emerging environmental pollutant and its removal from wastewater is very urgent. In this study, different alkyl substituted ionic liquids (1-alkyl -3-vinyl- imidazolium bromide [CVIm]Br, n = 4, 6, 8, 10, 12) functionalized tragacanth gum (TG-CBr) are prepared by radiation induced grafting and crosslinking polymerization. The adsorption behaviors of ionic liquids functionalized tragacanth gum for diclofenac sodium from aqueous solutions are examined.
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