The redox-neutral dicarbofunctionalization of tri- and tetrasubstituted olefins to form a variety of (hetero)cyclic compounds under photoinduced palladium catalysis is described. This cascade reaction process was used to couple styrenes or acryl amides with a broad range of highly decorated olefins tethered to aryl or alkyl bromides (>50 examples). This procedure enables one or two contiguous all-carbon quaternary centers to be formed in a single step. The products could be readily diversified and applied in the synthesis of a bioactive oxindole analogue.
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http://dx.doi.org/10.1002/anie.201911012 | DOI Listing |
Chem Commun (Camb)
January 2025
Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India.
Herein, we have developed a Pd(II)-catalyzed cyclization of prochiral alkyne-tethered malononitriles to access five-membered carbocycles having a nitrile-containing all-carbon quaternary center. The reaction pathway involves a -acetoxypalladation, nitrile group insertions into the carbon-palladium bond and sequential deacetylation followed by -acetylation. Initial studies on asymmetric cyclization were also performed with chiral Pyox ligands.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan 430079, P. R. China.
-cycloalkenes are abundant in bioactive natural products and have been used as powerful tools in chemical biology and drug discovery. However, strategies for the modular synthesis of -cycloalkenes, especially planar-chiral medium-sized ones, with high efficiency and selectivity, still remain elusive. Herein, we report a Pd-catalyzed asymmetric [7 + 2] cyclization strategy to address this challenge.
View Article and Find Full Text PDFOrg Lett
January 2025
Hubei Research Center of Fundamental Science-Chemistry, Engineering Research Center of Organosilicon Compounds & Materials, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, and College of Chemistry and Molecular Sciences, Wuhan University, 299 Bayi Rd, Wuhan 430072, China.
An enantioselective oxypalladation/malononitrile addition cascade reaction of alkyne-tethered malononitriles was reported to synthesize enaminones bearing an all-carbon quaternary center. Using Pd(TFA)/Pyox as a precatalyst, an array of enaminone products were obtained in moderate overall yields, with excellent er (93.5:6.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Chongqing Research Center for Pharmaceutical Engineering, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China.
A novel palladium-catalyzed allylic C-H alkylation of terminal olefins with 3-carboxamide oxindoles is described. A variety of new 3-carboxamide-3-allylation oxindoles with an all-carbon quaternary center were obtained in moderate to good yields (up to 99%). In addition, the asymmetric version of this reaction was also explored, providing moderate enantioselectivity.
View Article and Find Full Text PDFChem Sci
January 2025
Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology (SCUT) Guangzhou 510640 China.
Radical-mediated dearomatization strategies offer a blueprint for building value-added and synthetically valuable three-dimensional skeletons from readily available aromatic starting materials. Herein, we report a novel strategy by leveraging benzene-linked O-oxime esters as triply functionalized precursors to form two distinct persistent radicals under a chemodivergent pathway. These radicals then couple with a cyclohexadienyl radical for either carboamination or carbo-aminoalkylation.
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