The first examples of C[double bond, length as m-dash]S induced Pauson-Khand type reactions are described; 2-alkynylphenyl isothiocyanates were converted to 3-substituted-2H-thieno[2,3-b]indol-2-ones in the presence of a stoichiometric amount of Mo(CO)(6) or Co(2)(CO)(8), or a catalytic amount of Rh catalyst under an atmospheric pressure of carbon monoxide.
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http://dx.doi.org/10.1039/b712739a | DOI Listing |
Nat Commun
December 2024
Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Marine cyclopianes are a family of diterpenoid with novel carbon skeleton and diverse biological activities. Herein, we report our synthetic and chemical proteomics studies of cyclopiane diterpenes which culminate in the asymmetric total synthesis of conidiogenones C, K and 12β-hydroxy conidiogenone C, and identification of Immunity-related GTPase family M protein 1 (IRGM1) as a cellular target. Our asymmetric synthesis commences from Wieland-Miescher ketone and features a sequential intramolecular Pauson-Khand reaction and gold-catalyzed Nazarov cyclization to rapidly construct the 6-5-5-5 tetracyclic skeleton.
View Article and Find Full Text PDFScience
February 2024
RWTH Aachen University, Institute of Organic Chemistry, Landoltweg 1, D-52074 Aachen, Germany.
The Pauson-Khand reaction has in the past 50 years become one of the most common cycloaddition reactions in chemistry. Coupling two unsaturated bonds with carbon monoxide, the transformation remains limited to CO as a C building block. Herein we report analogous cycloaddition reactions with nitrenes as an N unit.
View Article and Find Full Text PDFBioorg Chem
October 2023
Guangdong Provincial Key Laboratory of Research and Development of Natural Drugs, and School of Pharmacy, Guangdong Medical University, Dongguan 523808, PR China; Shenzhen Institute of Geriatrics, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, PR China. Electronic address:
A flexible asymmetric synthesis of both enantiomers of euphopilolide (1) and jolkinolide E (2) [(+)-and (-)-1, (+)-and (-)-2] has been accomplished. This synthesis features an intramolecular oxa-Pauson-Khand reaction (o-PKR) to expeditiously construct the challenging tetracyclic [6.6.
View Article and Find Full Text PDFJ Am Chem Soc
May 2023
Shenzhen Grubbs Institute, Department of Chemistry, Guangming Advanced Research Institute, Southern University of Science and Technology, Shenzhen 518055, China.
The first total synthesis of (±)- and (-)-daphnillonin B, a daphnicyclidin-type alkaloid with a new [7-6-5-7-5-5] A/B/C/D/E/F hexacyclic core, has been achieved. The [6-5-7] B/C/D ring system was efficiently and diastereoselectively constructed via a mild type I intramolecular [5+2] cycloaddition, followed by a Grubbs II catalyst-catalyzed radical cyclization. The [5-5] fused E/F ring system was synthesized via a diastereoselective intramolecular Pauson-Khand reaction.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
June 2023
Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, K7L 3N6, Canada.
An enantioselective rhodium(I)-catalyzed Pauson-Khand reaction (PKR) using 1,6-chloroenynes that contain challenging 1,1-disubstituted olefins is described. In contrast to the previous studies with these types of substrates, which are only suitable for a single type of tether and alkyne substituent, the new approach results in a more expansive substrate scope, including carbon and heteroatom tethers with polar and non-polar substituents on the alkene. DFT calculations provide critical insight into the role of the halide, which pre-polarizes the alkyne to lower the barrier for metallacycle formation and provides the proper steric profile to promote a favorable enantiodetermining interaction between substrate and chiral diphosphine ligand.
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