The nickel-catalyzed enantioselective addition of allylboronic acid pinacol ester, allylB(pin), is described. This reaction is highly effective with dialkylidene ketones and favors the allylation of the benzylidene site in nonsymmetric substrates. The reaction appears to proceed by conversion of the dialkylidene ketone substrate to an unsaturated pi-allyl complex (I), followed by reductive elimination. Enantioselectivities range from 91 to 94% ee for a range of substrates when chiral ligand 14 is employed.
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http://dx.doi.org/10.1021/ja710922h | DOI Listing |
Sci Bull (Beijing)
December 2024
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address:
Divergent synthesis of valuable molecules through common starting materials and metal catalysis represents a longstanding challenge and a significant research goal. We here describe chemodivergent, highly enantio- and regioselective nickel-catalyzed reductive and dehydrogenative coupling reactions of alkynes, aldehydes, and silanes. A single chiral Ni-based catalyst is leveraged to directly prepare three distinct enantioenriched products (silyl-protected trisubstituted chiral allylic alcohols, oxasilacyclopentenes, and silicon-stereogenic oxasilacyclopentenes) in a single chemical operation.
View Article and Find Full Text PDFChem Sci
January 2025
Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University Yanxiang Road 99 Xi'an 710045 China
The first Ni-catalyzed asymmetric decarboxylative strategy for the construction of carbocycles with contiguous quaternary all-carbon stereocenters is reported. The key to the success of these reactions is the utilization of rationally designed allenylic methylene cyclic carbonates as substrates with Ni catalysis. The floppy allenylic group exerts unique electronic properties on the carbonate, which allows further asymmetric nucleophilic annulations with alkenes.
View Article and Find Full Text PDFOrg Lett
December 2024
College of Chemistry and Materials Science, Hengyang Normal University, Hengyang 421000, People's Republic of China.
Herein we successfully utilize various directing groups to achieve a ligand-enabled nickel-catalyzed 1,2-borylalkylation of unactivated alkenes. A β-amino alcohol was employed as the ligand for non-asymmetric 1,2-borylalkylation of unactivated alkenes, while a bulky chiral diamine ligand was used to achieve the asymmetric 1,2-borylalkylation of allyl amides.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Guangming Advanced Research Institute, Department of Chemistry, and Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and Technology, Shenzhen Grubbs Institute, Shenzhen, Guangdong, 518055, P. R. China.
Enantioenriched unsymmetric dialkyl carbinol derivatives are of importance in natural products, bioactive molecules, and functional organic materials. However, the catalytic asymmetric synthesis of dialkyl carbinol derivatives remains challenging due to the similar steric and electronic properties of two alkyl substituents. Herein, an unprecedented synthesis of chiral dialkyl carbinol ester derivatives from Ni-catalyzed reductive-oxidative relay cross-coupling of two alkenes is developed for the first time.
View Article and Find Full Text PDFJ Am Chem Soc
October 2024
The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States.
α-Aryl imides are common structural motifs in bioactive molecules and proteolysis-targeting chimeras designed for targeted protein degradation. An asymmetric Ni-catalyzed reductive cross-coupling of imide electrophiles and (hetero)aryl halides has been developed to synthesize enantioenriched α-arylglutarimides from simple starting materials. Judicious selection of electrophile pairs allows for coupling of both electron-rich and electron-deficient (hetero)aryl halides in good yields and enantioselectivities.
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