A library of modular iridium complexes derived from thioether-phosphite/phosphinite ligands has been evaluated in the asymmetric iridium-catalyzed hydrogenation of minimally functionalized olefins. The modular ligand design has been shown to be crucial in finding highly selective catalysts for each substrate. A DFT study of the transition state responsible for the enantiocontrol in the Ir-catalyzed hydrogenation is also described and used for further optimization of the crucial stereodefining moieties. Excellent enantioselectivities (enantiomeric excess (ee) values up to 99 %) have been obtained for a range of substrates, including E- and Z-trisubstituted and disubstituted olefins, α,β-unsaturated enones, tri- and disubstituted alkenylboronic esters, and olefins with trifluoromethyl substituents.
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http://dx.doi.org/10.1002/chem.201402978 | DOI Listing |
Molecules
December 2024
Department of Organic Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China.
In this study, an iridium-catalyzed selective 1,4-reduction of α,β-unsaturated carbonyl compounds is realized, with water as a solvent and formic acid as a hydride donor. The new efficient iridium catalyst features a 2-(4,5-dihydroimidazol-2-yl)quinoline ligand. The chemoselectivity and catalyst efficiency are highly dependent on the electronic and steric properties of the substrates.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Department of Chemistry and Medi-X Pingshan, Southern University of Science and Technology, Shenzhen 518055, People's Republic of China.
The iridium-catalyzed asymmetric hydrogenation of α-alkoxy-β-ketoesters dynamic kinetic resolution has been achieved with high efficiency and enantioselectivity. This strategy allows for the synthesis of differentiated -1,2-diol derivatives in high yields, exhibiting excellent enantio- and diastereoselectivity (up to 99% yield, 99% ee, and 99 : 1 dr). Additionally, high turnover number (TON) experiments (up to 1000 TON) and gram-scale synthesis of a key fragment of the potential drug Tesaglitazar were successfully performed, highlighting the protocol's potential for broader applications.
View Article and Find Full Text PDFOrg Lett
December 2024
Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Spain.
RSC Adv
November 2024
The Affiliated Ganzhou Hospital, Jiangxi Medical College, Nanchang University Ganzhou 341000 Jiangxi Province P. R. China
Sulfonamides are valuable structural building blocks, bioactives, and pharmaceuticals. While there have been great achievements in the sulfonamidation of alkyl and alkenyl carbon, the sulfonamidation of alkynyl carbon has not been studied. Herein, we report the synthesis of -benzylated sulfonamides from alkoxy aryl alkynes and sulfonamides enabled by Ir-catalyzed reductive sulfonamidation using HCOH as a hydrogen donor.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemistry, Shenzhen Grubbs Institute, Southern University of Science and Technology, Shenzhen 518000, China.
A catalytic protocol for the iridium-catalyzed asymmetric hydrogenation (AH) of γ- or δ-hydroxy ketones to rapidly assemble various aliphatic enantioenriched tetrahydrofurans (THFs) or tetrahydropyrans (THPs) is disclosed. A wide range of enantioenriched THFs or THPs were obtained in high yields and excellent enantioselectivities (up to 99% and up to 96.5:3.
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