Direct C-H bond functionalization is an efficient method for modifying organic molecules. However, achieving high enantioselectivity and regioselectivity in asymmetric C-H functionalization, particularly of C(sp)-H bonds, remains challenging. This study introduces an enantioselective propargylic C(sp)-H acyloxylation using photoexcited copper catalysis. The reaction demonstrated tolerance for various alkynes and peroxides, producing chiral propargyl esters in high yields and enantiomeric excess. Furthermore, the method was successfully extended to a diverse array of carboxylic acids in the presence of di--butyl peroxide (DTBP), significantly broadening its applicability.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.orglett.4c03933 | DOI Listing |
J Am Chem Soc
December 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.
The direct enantioselective functionalization of C(sp)-H bonds in organic molecules could fundamentally transform the synthesis of chiral molecules. In particular, the enantioselective oxidation of these bonds would dramatically change the production methods of chiral alcohols and esters, which are prevalent in natural products, pharmaceuticals, and fine chemicals. Remarkable advances have been made in the enantioselective construction of carbon-carbon and carbon-nitrogen bonds through the C(sp)-H bond functionalization.
View Article and Find Full Text PDFOrg Biomol Chem
December 2024
School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin, 300384, China.
Herein, we report an enantioselective Pd/Cu-catalyzed sequential Heck/Sonogashira coupling reaction of electron-rich enamides with terminal alkynes as substrates. This transformation proceeds smoothly to afford 3-propargyl isoindolinone derivatives bearing quaternary stereogenic centers in moderate to good yields (43-77% yield) and good to excellent enantioselectivity (up to 93% ee). Functional groups such as halogen atoms (F, Cl, and Br), thienyl, and silyl moieties are tolerated well.
View Article and Find Full Text PDFChemistry
December 2024
Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh, Kanpur, 208016, India.
Herein, we report a copper-catalyzed enantioselective formal (3+3) and (3+2) cycloaddition reaction of isatin-derived tertiary propargylic esters with N,N-dimethylbarbituric acid and 4-hydroxycoumarins, respectively. In this process, the tertiary propargylic ester serves as both C3- and C2-synthons, facilitating the synthesis of optically active spirooxindole-pyran and furan scaffolds featuring an all-carbon quaternary stereocenter. The reaction delivers these spirocyclic frameworks in good yields with high enantioselectivities.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
Catalytic asymmetric α-alkylation of simple carboxylic acid derivatives is a challenging issue due to the difficulties in achieving high catalytic efficiency and controlling the enantioselectivity. Herein, by using a copper(I)-()-DTBM-SEGPHOS complex as a catalyst and 2-acylimidazoles as pronucleophiles, a general method for the catalytic asymmetric α-alkylation of simple carboxylic acid derivatives is accomplished. Various alkyl electrophiles, including allyl bromides, benzyl bromides, propargyl bromide, and unactivated alkyl sulfonates, serve as efficient alkylation reagents.
View Article and Find Full Text PDFBeilstein J Org Chem
November 2024
Department of Chemistry and Chemical Engineering, Florida Institute of Technology, 150 West University Boulevard, Melbourne, Florida 32901-6975, USA.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!