An asymmetric organocatalytic direct arylation approach to construct arylated quaternary stereogenic centers with a catalyst loading of 1 mol % is reported. The formation of the hemiketal moiety in stabilizing the hydroquinone intermediate proves to be important in leading to hydroquinone products instead of oxidation quinone products obtained in previously reported methods. A series of structurally and stereochemically complex heterocyclic frameworks are obtained, including spiro-, dispiro-, fused, and bridged heterocycles.
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http://dx.doi.org/10.1021/acs.orglett.8b00377 | DOI Listing |
Cell Chem Biol
December 2024
Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Computational and Integrative Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA. Electronic address:
Chemical inducers of proximity (CIPs) are molecules that recruit one protein to another and introduce new functionalities toward modulating protein states and activities. While CIP-mediated recruitment of E3 ligases is widely exploited for the development of degraders, other therapeutic modalities remain underexplored. We describe a non-degrader CIP-DNA-encoded library (CIP-DEL) that recruits FKBP12 to target proteins using non-traditional acyclic structures, with an emphasis on introducing stereochemically diverse and rigid connectors to attach the combinatorial library.
View Article and Find Full Text PDFProteins
January 2025
Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.
Lactoperoxidase (LPO) is a heme-containing mammalian enzyme that is found in the extracellular fluids of animals including plasma, saliva, airway epithelial and nasal lining fluids, milk, tears, and gastric juices. LPO uses hydrogen peroxide (HO) to convert substrates into oxidized products. Previous structural studies have shown that HO, CO, and CN are bound to LPO at the distal heme cavity by coordinating with heme iron.
View Article and Find Full Text PDFMagn Reson Chem
January 2025
A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia.
The complete H and C NMR assignments of a trimeric vindoline together with its individual components, dimeric vindolicine and monomeric vindoline, are performed based on a thorough analysis of the ROESY, COSY, HSQC, and HMBC spectra in combination with the state-of-the-art quantum-chemical calculations. A spatial structure of vindoline trimer is determined by means of computational conformational analysis in combination with the probability distribution map of its basic conformers. On the example of monoterpene indole alkaloid, the trimer vindoline, the present study reveals the power of modern computational NMR to perform identification and stereochemical studies of large natural compounds with some limitations, which may arise in the quantum chemical computing workflow.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
National University of Singapore Department of Chemistry, Department of Chemistry, 3 Science Drive 3, 117543, Singapore, SINGAPORE.
Asymmetric synthesis relies on seamless transmission of stereochemical information from a chiral reagent/catalyst to a prochiral substrate. The disruption by substrates' structural changes presents a hurdle in innovating generality-oriented asymmetric catalysis. Here, we report a strategy for substrate adaptability by exploiting a fundamental physicochemical phenomenon-ion hydration, in developing remote desymmetrization to access P-stereogenic triarylphosphine oxides and sulfides.
View Article and Find Full Text PDFJ 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.
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