Enantioselective α-aminomethylation of carbonyl compounds constitutes a powerful protocol for introducing aminomethyl groups to simple organic molecules. However, current strategies rely on nucleophile-based enantioselective activation with inherently activated substrates only, and enantioselective protocol based on the activation of in situ-generated unstable formaldimines remains elusive, probably owing to their unstable nature and the lack of steric environment for efficient stereocontrols. Here, based on a rhodium/chiral phosphoric acid cooperative catalysis, we achieved an enantioselective three-component reaction of α-diazo ketones with alcohols and 1,3,5-triazines. A dual hydrogen bonding between the chiral phosphoric acid catalyst and two distinct active intermediates was proposed to be crucial for the efficient electrophile-based enantiocontrol. A series of chiral β-amino-α-hydroxy ketones including those derived from simple aliphatic alcohols, allylic alcohol, propargyl alcohol, complicated natural alcohols and water could all be prepared in high efficiency and enantioselectivity.
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http://dx.doi.org/10.1038/s41467-020-15345-2 | DOI Listing |
Org Lett
January 2025
Department of Chemistry, College of Science, China Agricultural University, 2 Yuanmingyuan West Road, Beijing 100193, P. R. China.
A three-component cascade boronation-dearomatization reaction of alkenes, a diboron compound, and a pyridinium salt is diclosed, affording chiral boron-containing 1,4-dihyropyridines in high yields (≤98%) and diastereoselectivity (≤10:1 dr), along with excellent enantioselectivity (typically >99% ee). The catalytic system performs efficiently at low catalyst loadings (1 mol %) and was tested with >50 examples, including some biologically active molecules.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Organisch-Chemisches Institut, Universität Münster, Münster 48149, Germany.
Nozaki-Hiyama-Kishi (NHK) reactions offer a mild approach for the formation of alcohol motifs through radical-polar crossover-based pathways from various radical precursors. However, the application of multicomponent NHK-type reactions, which allow the formation of multiple bonds in a single step, has been largely restricted to bulky alkyl radical precursors, thus limiting their expanded utilization. Herein, we disclose a general three-component NHK-type reaction enabled by delayed radical-polar crossover, which efficiently tolerates a plethora of radical precursors that were previously unavailable.
View Article and Find Full Text PDFOrg Lett
January 2025
Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, Shanghai Key Laboratory of New Drug Design, and School of Pharmacy, East China University of Science and Technology, Shanghai 200237, P. R. China.
The efficient construction of chiral aryl-containing organosilicon frameworks via catalytic enantioselective three-component silylarylation of alkenes remains a great challenge. Herein, a photoredox/nickel dual-catalytic asymmetric protocol has been disclosed by using a chiral biimidazoline (BiIM) as the ligand, silylboranes as the silyl radical precursors, aryl bromides as the coupling partners, and morpholine as the promoter. Remarkably, the reaction features mild and green conditions, high reaction efficiency, and excellent enantioselectivity, enabling the facile synthesis of valuable chiral tropic acid and sila-isoflavanone structures.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Laboratory of Asymmetric Catalysis and Synthesis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
Asymmetric -heterocyclic carbene (NHC) organocatalysis is a cornerstone of synthetic organic chemistry. The emerging concept of single-electron NHC catalysis broadened the scope of C-C bond-forming reactions, facilitating the synthesis of a variety of attractive racemic compounds. However, the development of effective and selective chiral NHC catalysts for asymmetric radical-mediated reactions has been challenging.
View Article and Find Full Text PDFNature
November 2024
State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), ChemBioMed Interdisciplinary Research Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China.
Multicomponent reactions - those where three or more substrates combine into a product - have been highly useful in rapidly building chemical building blocks of increased complexity, but achieving this enzymatically has remained rare. This limitation primarily arises because an enzyme's active site is not typically set up to address multiple substrates, especially in cases involving multiple radical intermediates. Recently, chemical catalytic radical sorting has emerged as an enabling strategy for a variety of useful reactions.
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