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By introducing a carbon functionality at 2-position of chromane, the formal asymmetric functionalization of the 3-position of 2-substituted chromane has been realized via a highly chemo-, regio-, and stereoselective organocatalytic cascade reaction in a sequential one-pot manner involving an E1cB mechanism governed ring-opening process. Critical to our success was the design of a chiral dipeptide-based bifunctional acid-base organocatalyst, which exhibited high catalytic activity at low catalyst loading (1-0.1 mol %), leading to biologically interesting polyheterocyclic compounds.
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http://dx.doi.org/10.1021/acs.orglett.9b03138 | DOI Listing |
ChemSusChem
September 2025
Organic Chemistry Institute, University of Münster, Corrensstraße 36, 48149, Münster, Germany.
A three-step, one-pot, sequential cascade starting from simple feedstocks to increase complexity toward value-added chiral synthetic building blocks is reported. This is achieved by precisely integrating organic photocatalysis and noncovalent organocatalysis, often operating at dissimilar conditions and reaction media. In particular, this strategy is used to enable the direct transformation of readily available benzylic substrates, such as methylbenzenes, benzyl alcohols, or amines, into enantioenriched α-aminonitriles by benzylic CH photooxidation to their corresponding aldehydes, followed by in situ imine formation and final asymmetric organocatalytic Strecker reaction.
View Article and Find Full Text PDFJ Org Chem
September 2025
Department of Chemistry, Scripps Research, La Jolla, California 92037, United States.
Many high-profile catalytic reactions in modern organic synthesis involve coupled multicycle networks, with key examples including organocatalytic cascade reactions and photochemical and electrochemical systems. Distinct catalytic cycles combine to operate as connected "cogs" within the overall reaction network. In these cases, one cycle may produce a product that is subsequently delivered as a substrate to a second cycle, and one or more catalytic intermediate species may be shared between multiple catalytic cycles.
View Article and Find Full Text PDFOrg Lett
August 2025
Department of Chemistry, National Taiwan Normal University, 88, Sec. 4, Tingchow Road, Taipei 11677, Taiwan, R.O.C.
We report a streamlined organocatalytic enantioselective construction of spiro-fused polycyclic scaffolds, achieving excellent yields and diastereo- and enantioselectivities. A bifunctional squaramide catalyst enables an asymmetric VMA reaction, followed by a proton transfer/aldol/acetalization cascade of vinylogous pyrazolones with trifluoroacetyl-tethered enediones. Additionally, the scalability and postsynthetic transformations of the titled products highlight their synthetic utility.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2025
University of Bordeaux, CNRS, Bordeaux INP, Laboratoire de Chimie des Polymères Organiques (LCPO), UMR 5629, 16 Av. Pey Berland, Pessac cedex, 33607, France.
Cyclic carbonates, in particular ethylene carbonate (EC), are pivotal compounds across chemical sciences because of their unique properties. Although, their transformation into valuable products has attracted great attention, efficient and selective transformations remain challenging. In this work, we report a catalytic system composed of Ru nanoparticles (RuNPs) stabilized by poly(ionic liquids) (Ru@PIL), that enables the selective chemo-divergent hydrogenation of EC into either EtOH and CO or EG and CH, under solvent-free conditions.
View Article and Find Full Text PDFAn asymmetric synthesis of spiro[indoline-3,1'-pyrazolo[1,2-]phthalazine] derivatives was first developed through an organocatalysed cascade Knoevenagel/Michael/cyclization reaction using a quinidine-derived squaramide. Under the optimized conditions, the three-component reaction of isatins, malononitrile (cyanoacetate) and phthalhydrazide yields the desired pyrazolophthalazinyl spirooxindoles in good yields (73-90%) with up to >99% enantiomer excess (ee).
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