Results 21 to 30 of about 177,307 (324)

X-ray Diffraction, Electronic Circular Dichroism, and Quantum Mechanics (TD-DFT) Investigations on 4 Dehydroxyaltersolanol A, a Secondary Metabolite from Endophytic Fungus Nigrospora oryzae [PDF]

open access: yesResearch Journal of Pharmacognosy
Background and objectives: A tetrahydro anthraquinone derivative, 4-dehydroxyaltersolanol A, has been obtained from Nigrospora oryzae, which was isolated from Uncaria borneensis Havil as an endophytic fungus.
Fatimah Bebe Mohamed Hussain   +8 more
doaj   +1 more source

RDChiral: An RDKit Wrapper for Handling Stereochemistry in Retrosynthetic Template Extraction and Application

open access: yesJournal of Chemical Information and Modeling, 2019
There is a renewed interest in computer-aided synthesis planning, where the vast majority of approaches require the application of retrosynthetic reaction templates.
Connor W. Coley, W. Green, K. Jensen
semanticscholar   +1 more source

Nucleophilic Substitution at Heteroatoms—Identity Substitution Reactions at Phosphorus and Sulfur Centers: Do They Proceed in a Concerted (SN2) or Stepwise (A–E) Way?

open access: yesMolecules, 2022
The mechanisms of three selected identity substitution reactions at phosphorus and sulfur occurring with stereospecific inversion have been investigated using density functional theory (DFT).
Marian Mikołajczyk   +3 more
doaj   +1 more source

Atropselective syntheses of (-) and (+) rugulotrosin A utilizing point-to-axial chirality transfer [PDF]

open access: yes, 2015
Chiral, dimeric natural products containing complex structures and interesting biological properties have inspired chemists and biologists for decades.
A Zask   +53 more
core   +2 more sources

Contribution of the Chemistry Institutes to the Early Development of Stereochemistry

open access: yesCHIMIA, 2009
This article is a translation from German of a paper submitted by Kurt Hermann to the University of Zurich Prize committee in 1968, with additional editing by Jay Siegel.
Kurt Hermann
doaj   +1 more source

The Metallacyclopentane-Olefin Interchange Reaction [PDF]

open access: yes, 1977
Tris(triphenylphosphine)tetramethylenenickel(II) and biscyclopentadienyltetramethylenetitanium, prepared from the reaction of a 1,4-dilithiobutane and the transition metal dihalides react with olefins to produce substituted metallacyclopentanes; the ...
Grubbs, Robert H., Miyashita, Akira
core   +1 more source

DESIGN OF AN EDUCATIONAL GAME AND ITS USE IN A TEAM GAME TOURNAMENT AS A STRATEGY TO ENGAGE STUDENTS IN REVIEWING STEREOCHEMISTRY CONCEPTS [PDF]

open access: yesQuímica Nova
This paper presents a Chemistry Team Game Tournament (TGT) as a didactic strategy to review stereochemistry concepts. For this purpose, a multilingual (English, Italian, French, and Portuguese) educational game, Stereochemistry Race, was developed on the
José Nunes da Silva Júnior   +8 more
doaj   +1 more source

Ortho‐Quinone Methide Driven Synthesis of New O,N‐ or N,N‐Heterocycles

open access: yesChemistryOpen, 2019
To synthesize functionalized Mannich bases that can serve two different types of ortho‐quinone methide (o‐QM) intermediates, 2‐naphthol and 6‐hydroxyquinoline were reacted with salicylic aldehyde in the presence of morpholine.
Dr. István Szatmári   +5 more
doaj   +1 more source

Diatoms synthesize sterols by inclusion of animal and fungal genes in the plant pathway [PDF]

open access: yes, 2020
Diatoms are ubiquitous microalgae that have developed remarkable metabolic plasticity and gene diversification. Here we report the first elucidation of the complete biosynthesis of sterols in the lineage.
, Angela   +7 more
core   +1 more source

Focus on chirality of HIV-​1 non-​nucleoside reverse transcriptase inhibitors [PDF]

open access: yes, 2016
Chiral HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) are of great interest since one enantiomer is often more potent than the corresponding counterpart against the HIV-1 wild type (WT) and the HIV-1 drug resistant mutant strains.
Famiglini, Valeria, Silvestri, Romano
core   +2 more sources

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