The use of flow methodology allows the use of alkynylphenyl vinyl ethers (benzo-fused 1,7 enynes) as substrates for the intramolecular Pauson-Khand reaction (PKr). Forced temperature and pressure conditions during a short reaction time minimize the substrate decomposition allowing the formation of the PK adduct. Substrates substituted at the internal position of the double bond and with internal triple bonds give better yields. The resulting products are cyclopentabenzofuranones present in diverse natural products and drugs that can be further functionalised.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8982164 | PMC |
http://dx.doi.org/10.1039/d2ra01062c | DOI Listing |
J Am Chem Soc
December 2024
Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States.
We report a stereo-differentiating dynamic kinetic asymmetric Rh(I)-catalyzed Pauson-Khand reaction, which provides access to an array of thapsigargin stereoisomers. Using catalyst-control, a consistent stereochemical outcome is achieved at C2─for both matched and mismatched cases─regardless of the allene-yne C8 stereochemistry. The stereochemical configuration for all stereoisomers was assigned by comparing experimental vibrational circular dichroism (VCD) and C NMR to DFT-computed spectra.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, and Chemical Biology Center, Peking University, 38 Xueyuan Road, Beijing 100191, China.
J Am Chem Soc
December 2024
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Euphorbialoid A () belongs to the rare diterpenoid family of premyrsinanes and exhibits potent anti-inflammatory effects. The 5/7/6/3-membered carbocycle (ABCD-ring) of contains 11 contiguous stereocenters and seven oxygen-containing functional groups. Moreover, four of the six hydroxy groups of are concentrated in the southern sector and flanked by four structurally different acyl groups.
View Article and Find Full Text PDFJACS Au
November 2024
Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
(-)-Bipolarolide D is an ophiobolin-derived sesteterpenoid with a unique tetraquinane (5/5/5/5) tetracyclic skeleton decorated with a diverse set of functionalities. Herein we report a robust, scalable, and efficient total synthesis of this natural product in 1.8% overall yield.
View Article and Find Full Text PDFJ Phys Chem A
December 2024
Department of Chemistry, Indian Institute of Technology Jammu, Jammu 181221, India.
Enantioselective catalytic reactions have a significant impact on chemical synthesis, and they are important components in an experimental chemist's toolbox. However, development of asymmetric catalysts often relies on the chemical intuition and experience of a synthetic chemist, making the process both time-consuming and resource-intensive. The machine-learning-assisted reaction discovery can serve as a very efficient platform for obtaining high-performing catalysts in a time-economical manner without extensive experimentation.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!