The enantioselective reaction of α-substituted β-nitroacrylates with oxazol-5-(4)-ones (oxazolones) to construct consecutive tetrasubstituted stereogenic centers was accomplished. A cinchona alkaloid sulfonamide catalyst afforded products bearing vicinal chiral centers with excellent enantio- and diastereoselectivities. The obtained products were successively converted into various chiral compounds without loss of their enantiopurity. Furthermore, density functional theory (DFT) calculations were performed to elucidate the mechanism and origin of the observed stereoselectivity of the reaction.
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http://dx.doi.org/10.1021/acs.orglett.3c00783 | DOI Listing |
J Am Chem Soc
January 2025
Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Direct synthesis of enantioenriched scaffolds with multiple adjacent stereocenters remains an important yet challenging task. Herein, we describe a highly diastereo- and enantioselective Cu-catalyzed alkylboration of cyclopropenes, with less reactive alkyl iodides as electrophiles, for the efficient synthesis of -substituted borylated cyclopropanes bearing three consecutive stereocenters. This protocol features mild conditions, a broad substrate scope, and good functional group tolerance, affording an array of chiral borylated cyclopropanes in good to high yields with excellent diastereo- and enantioselectivities.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Center for Advanced Technologies, Adam Mickiewicz University, Uniwersytetu Poznanskiego 10, 61-614 Poznan, Poland.
A novel approach towards synthesizing new metalloid-substituted olefins has been accomplished by transforming ()-1,2-diboryl-1-silylethenes through two consecutive Suzuki-Miyaura coupling reactions. This methodology provides an effective and selective way to obtain new, structurally different products, such as ()-1-silyl-1-boryl-2-arylethens, (1)-1-silyl-1-boryl-2-alkenylethens, and ()-1-silyl-1-aryl-2-arylethenes, which are difficult to synthesize through hydrometallation reactions and related processes. Due to the presence of reactive motifs (silyl group, Bpin moiety, and C-H bond) in the structure of the final products, these molecules might be considered powerful building blocks in modern chemistry.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Key Laboratory of Molecule Synthesis and Function Discovery, Fujian Province University, College of Chemistry at Fuzhou University, Fuzhou, Fujian, 350108, China.
Zweifel reaction is a powerful strategy to construct olefins from alkenyl tetracoordinate borons in organoboron chemistry, however, it usually only involves one functional group migration and then undergoes an elimination process affording alkenes or alkynes exclusively. Herein, we disclose several intriguing interception of alkynyl tetracoordinate borons with sulfur electrophiles. Wherein, the substituted benzothiophenes are accessed by consecutive 1,2-migrations and intramolecular electrophilic substitution, meanwhile, the challenging and elusive five/four-membered boracycles are easily assembled, and an approach to alkenyl sulfides with good stereoselectivity was developed as well.
View Article and Find Full Text PDFChem Asian J
December 2024
Department of Chemistry, Istanbul Technical University Maslak, 34469, Istanbul, Türkiye.
In this study, two novel tetra-substituted manganese (III) phthalocyanines bearing (9H-carbazol-2-yl)oxy groups on peripheral (1) or non-peripheral (2) positions were prepared and used for modification of reduced graphene oxide (rGO) by applying a simple one-step electrodeposition technique for the first time. The manganese (III) phthalocyanines (MnPcs) were electropolymerized and graphene oxide was electrochemically converted into reduced graphene oxide simultaneously. Subsequently, an rGO-MnPc hybrid structure was formed directly on the NiF electrode (substrate) via layer-by-layer assembly.
View Article and Find Full Text PDFOrg Lett
April 2023
Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya 466-8555, Japan.
The enantioselective reaction of α-substituted β-nitroacrylates with oxazol-5-(4)-ones (oxazolones) to construct consecutive tetrasubstituted stereogenic centers was accomplished. A cinchona alkaloid sulfonamide catalyst afforded products bearing vicinal chiral centers with excellent enantio- and diastereoselectivities. The obtained products were successively converted into various chiral compounds without loss of their enantiopurity.
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