The complicated mechanism makes the regiodivergent rearrangement of ammonium ylide seem to be out of reach. Herein, we reported a regiodivergent rearrangement of gramine ammonium ylide well controlled by the substituents. Density functional theory studies reveal that the ammonium ylide with a more steric hindrance substituent 2-diazo-2-arylacetate goes through a stepwise mechanism to yield both a kinetically and thermodynamically preferred [1,2]-rearrangement product. In contrast, the ammonium ylide with a less steric hindrance ethyl diazoacetate goes through a concerted mechanism to generate the [2,3]-rearrangement product, which is kinetically favored as a result of the release of the ring strain in the transition state. This study would open up avenues to grasp the rearrangement of ammonium ylide, which will promote application in the skeletal editing and synthesis of complex natural products.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.joc.4c02698 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Substituent-Controlled Regiodivergent Rearrangement of Gramine Ammonium Ylide.
J Org Chem
January 2025
Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou 570228, P.R. China.
The complicated mechanism makes the regiodivergent rearrangement of ammonium ylide seem to be out of reach. Herein, we reported a regiodivergent rearrangement of gramine ammonium ylide well controlled by the substituents. Density functional theory studies reveal that the ammonium ylide with a more steric hindrance substituent 2-diazo-2-arylacetate goes through a stepwise mechanism to yield both a kinetically and thermodynamically preferred [1,2]-rearrangement product.
View Article and Find Full Text PDFIn-Cage Recombination Facilitates the Enantioselective Organocatalytic [1,2]-Rearrangement of Allylic Ammonium Ylides.
J Am Chem Soc
January 2025
EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St. Andrews, KY16 9ST, U.K.
The [1,2]-rearrangement of allylic ammonium ylides is traditionally observed as a competitive minor pathway alongside the thermally allowed [2,3]-sigmatropic rearrangement. Concerted [1,2]-rearrangements are formally forbidden, with these processes believed to proceed through homolytic C-N bond fission of the ylide, followed by radical-radical recombination. The challenges associated with developing a catalytic enantioselective [1,2]-rearrangement of allylic ammonium ylides therefore lie in biasing the reaction pathway to favor the [1,2]-reaction product, alongside controlling a stereoselective radical-radical recombination event.
View Article and Find Full Text PDFBicyclic-Ammonium-Incorporated Ylidic Nitrogen Groups for Strong π-Electron Donation in Push-Pull Benzene π-Conjugated Systems.
Org Lett
September 2024
Faculty of Pharmaceutical Sciences, Institute of Medical, Pharmaceutical, and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
Ylidic nitrogen-based π-electron-donating groups, (quinuclidinio)amidyl (QA) and (1-azanorbornanio)amidyl (ANA) groups, were developed to shift the absorption of push-pull benzenes toward longer wavelengths. Changing the pyrrolidinyl group to the QA or ANA group achieved a bathochromic shift of 45-100 nm in the maximum absorption wavelength, depending on the push-pull π-conjugated system investigated (-nitrobenzene, 1,8-naphthalimide, and an azo dye).
View Article and Find Full Text PDFScaffold overlay of flavonoid-inspired molecules: Discovery of 2,3-diaryl-pyridopyrimidin-4-imine/ones as dual hTopo-II and tubulin targeting anticancer agents.
Bioorg Chem
November 2024
Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, SAS Nagar, Mohali, Punjab 160062, India. Electronic address:
Almost half of all medicines approved by the U.S. Food and Drug Administration have been found to be developed based on inspiration from natural products (NPs).
View Article and Find Full Text PDFRelay Annulation of Ammonium Ylides with Oxindole-Derived α,β-Unsaturated Ketimines: Catalytic Construction of Spiro-polycyclic Oxindoles.
Org Lett
June 2024
Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
An ammonium ylide-based relay annulation was disclosed, which uses DABCO as the catalyst and oxindole-derived α,β-unsaturated ketimines and γ-bromo-crotonates as the starting materials. This method enables the rapid assembly of a series of structurally novel spiro-polycyclic oxindoles containing a bicyclo[4.1.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!