A palladium catalyzed, carbon monoxide mediated, double reductive cyclization of 1,4-, 1,3-, and 2,3-bis(2-nitroaryl)-1,3-butadienes to afford 2,2'-, 2,3'-, and 3,3'-biindoles, respectively, was developed. In contrast, reductive cyclizations of 1,2-bis(2-nitroaryl)ethenes were nonselective, affording mixtures of monocyclized indoles, indolo[3,2-b]indole, indolo[1,2-c]quinazolin-6(5H)-ones, and 5,11-dihydro-6H-indolo[3,2-c]quinolin-6-ones. Nonselective product formation was also observed from reductive cyclization of 1,1-bis(2-nitroaryl)ethenes, producing indolo[2,3-b]indoles and indolo[2,3-c]quinolin-6-ones. Carbon monoxide insertion to give the carbonyl containing products was the major or sole reaction path starting from 1,1- or 1,2-bis(2-nitroaryl)ethenes.
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http://dx.doi.org/10.1021/acs.joc.6b01987 | DOI Listing |
Nat Commun
January 2025
Shenzhen Grubbs Institute and Department of Chemistry, Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen, Guangdong, China.
3-Amino boron dipyrromethenes (BODIPYs) are a versatile class of fluorophores widely utilized in live cell imaging, photodynamic therapy, and fluorescent materials science. Despite the growing demand for optically active BODIPYs, the synthesis of chiral 3-amino-BODIPYs, particularly the catalytic asymmetric version, remains a challenge. Herein, we report the synthesis of boron-stereogenic 3-amino-BODIPYs via a palladium-catalyzed desymmetric C-N cross-coupling of prochiral 3,5-dihalogen-BODIPYs.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Institute for Integrated Programmes and Research in Basic Sciences (IIRBS), Mahatma Gandhi University, Priyadarsini Hills P O, Kottayam, Kerala 686 560, India.
-Alkylation of amines is a vital reaction in the synthesis of numerous bioactive compounds and materials. Among transition metals, palladium has emerged as a particularly effective catalyst for these transformations. The unique advantages of palladium arise from its superior catalytic efficiency, ability to operate under mild conditions, high selectivity and recyclability.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
School of Chemistry and Chemical Engineering, Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development, Guangxi University, Nanning 530004, Guangxi, P. R. China.
We present a mild and efficient method for the arylation of N-H heteroarenes using a low-loading Pd/keYPhos catalyst (0.8 mol%). This approach employs inexpensive and structurally diverse aryl chlorides as electrophiles in reactions with indoles, pyrroles, and carbazole, enabling the construction of a wide range of -arylated products.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
University of Melbourne, School of Chemistry, 30 Flemington Rd., VIC 3095, Parkville, AUSTRALIA.
Palladium(II)-catalyzed C-H functionalization has attracted considerable attention as a pathway to late-stage modification of peptides. Herein, we report the Pd-catalyzed C(sp3)-H arylation of peptides directed by an amidoxime ether, which can be easily incorporated into peptides at any amide bond. Site- and stereoselective arylation of peptides has been achieved, including an unprecedented example of C-H arylation of an internal residue.
View Article and Find Full Text PDFJ Org Chem
January 2025
Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, China.
Among the known aromatic -heterocycles, pyrroles are significant and versatile privileged components in pharmacologically relevant molecules. Herein, we demonstrate a protocol for the selective construction of alkynylated pyrroles in a diversity-oriented fashion through divergent C2/C5 site-selective alkynylation of pyrrole derivatives by employing a palladium catalyst with two different solvent systems. In the presence of 1,4-dioxane, the C2-alkynylation process via chelation-assisted palladation is favored.
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