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The stereoconvergent synthesis of a single stereoisomer from /-olefin mixtures remains one of the foremost challenges in organic synthesis. Herein, we describe a nickel-catalyzed stereoconvergent cross-coupling between - and -mixed monofluoroalkenes and alkenyl electrophiles, which allows the construction of C(sp)-C(sp) bonds. This defluorinative transformation offers facile access to various 1,3-dienes with -selectivity and good functional group tolerance. Preliminary mechanistic studies indicate that the reaction most likely proceeds through a migratory insertion/β-F elimination/isomerization process.
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http://dx.doi.org/10.1021/acs.orglett.4c03107 | DOI Listing |
Org Lett
November 2024
State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
As a class of versatile building blocks, chiral benzylic boronic esters are important intermediates employed in modern organic chemistry. We describe herein the first stereoconvergent multicomponent cross-coupling reaction of vinyl boronates, alkyltrifluoroborates, and aryl halides through a dual photoredox/nickel catalysis methodology. This synergistic platform permitted the benign construction of various enantioenriched benzylic boronic esters with broad substrate tolerance and moderate to excellent enantioselectivity (up to 98:2 ) from commercially available starting materials.
View Article and Find Full Text PDFOrg Lett
October 2024
State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China.
The stereoconvergent synthesis of a single stereoisomer from /-olefin mixtures remains one of the foremost challenges in organic synthesis. Herein, we describe a nickel-catalyzed stereoconvergent cross-coupling between - and -mixed monofluoroalkenes and alkenyl electrophiles, which allows the construction of C(sp)-C(sp) bonds. This defluorinative transformation offers facile access to various 1,3-dienes with -selectivity and good functional group tolerance.
View Article and Find Full Text PDFJ Am Chem Soc
August 2024
State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, China.
Stereoconvergent reactions enable the transformation of mixed stereoisomers into well-defined, chiral products─a crucial strategy for handling /-mixed olefins, which are common but challenging substrates in organic synthesis. Herein, we report a stereoconvergent and highly enantioselective method for synthesizing -homoallylic alcohols via the nickel-catalyzed reductive coupling of /-mixed 1,3-dienes with aldehydes. This process is enabled by an -heterocyclic carbene ligand characterized by -symmetric backbone chirality and bulky 2,6-diisopropyl -aryl substituents.
View Article and Find Full Text PDFOrg Lett
January 2024
Institute of Organic Chemistry, University of Vienna, Währinger Straße 38, 1090 Vienna, Austria.
A nickel-catalyzed reductive dimerization of bromocyclobutenes to produce unusual and unprecedented cyclobutene dimers was developed. In a stereoconvergent procedure, various bromocyclobutenes were readily dimerized in good yields, with good diastereoselectivities and broad functional group tolerance. Notably, the presence of a carbonyl group in the starting material appears to dictate diastereoselectivity.
View Article and Find Full Text PDFAcc Chem Res
December 2023
Department of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States.
Nickel excels at facilitating selective radical chemistry, playing a pivotal role in metalloenzyme catalysis and modern cross-coupling reactions. Radicals, being nonpolar and neutral, exhibit orthogonal reactivity to nucleophilic and basic functional groups commonly present in biomolecules. Harnessing this compatibility, we delve into the application of nickel-catalyzed radical pathways in the synthesis of noncanonical peptides and carbohydrates, critical for chemical biology studies and drug discovery.
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