Nonclassical ammonium ions as intermediates in cinchona alkaloid rearrangements?
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DOI: 10.1002/chir.23188
Abstract: The classical/nonclassical nature of cationic ammonium intermediates proposed to be involved in cinchona alkaloid solvolysis and related reactions is investigated. While these intermediates are found to possess highly distorted geometries in which the central nitrogen… read more here.
Keywords: ammonium ions; cinchona alkaloid; nonclassical ammonium; ammonium ... See more keywords
Endophyte composition and Cinchona alkaloid production abilities of Cinchona ledgeriana cultivated in Japan
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DOI: 10.1007/s11418-018-1273-z
Abstract: New eight endophytic filamentous fungi were isolated from the young stems of Cinchona ledgeriana (Rubiaceae) cultivated in Japan. They were classified into four genera based on phylogenetic analysis of the nucleotide sequences of the internal… read more here.
Keywords: cinchona alkaloid; cultivated japan; endophyte composition; cinchona ledgeriana ... See more keywords
Synthesis of chiral polyesters of cinchona alkaloid catalysts for enantioselective Michael addition of anthrone to nitroalkenes
Sign Up to like & getrecommendations! Published in 2018 at "Journal of Catalysis"
DOI: 10.1016/j.jcat.2018.03.020
Abstract: Abstract Chiral polyesters of cinchona alkaloid derivatives were synthesized via repetitive Mizoroki-Heck (MH) coupling reaction. Under MH reaction conditions, 4-iodobenzoylquinine and 4-iodobenzoylcupreine were easily polymerized via self polycondensation to afford the corresponding chiral polyesters. The… read more here.
Keywords: chiral polyesters; michael addition; cinchona alkaloid; polyesters cinchona ... See more keywords
Cinchona-Alkaloid-Derived NNP Ligand for Iridium-Catalyzed Asymmetric Hydrogenation of Ketones.
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DOI: 10.1021/acs.orglett.1c04101
Abstract: Most ligands applied for asymmetric hydrogenation are synthesized via multistep reactions with expensive chemical reagents. Herein, a series of novel and easily accessed cinchona-alkaloid-based NNP ligands have been developed in two steps. By combining [Ir(COD)Cl]2,… read more here.
Keywords: cinchona alkaloid; derived nnp; alkaloid derived; nnp ligand ... See more keywords
Cinchona Alkaloid Derived Iodide Catalyzed Enantioselective Oxidative α-Amination of Carbonyl Compounds toward the Construction of Spiroindolyloxindole.
Sign Up to like & getrecommendations! Published in 2022 at "Organic letters"
DOI: 10.1021/acs.orglett.1c04118
Abstract: Novel cinchona alkaloid derived iodide catalysts were developed for the enantioselective oxidative α-amination of 2-oxindoles, providing various functionalized spiropyrrolidine oxindoles in high yields and with good enantioselectivities. This iodide/ROOH catalytic system features a one-step synthesis… read more here.
Keywords: cinchona alkaloid; enantioselective oxidative; oxidative amination; alkaloid derived ... See more keywords
Spectroscopic Study of a Cinchona Alkaloid-Catalyzed Henry Reaction
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DOI: 10.1021/acsomega.7b01713
Abstract: A spectroscopic study of an organocatalytic Henry reaction between nitroalkanes and aldehydes catalyzed by a quinidine-derived Cinchona alkaloid is described. The binding modes of the reaction substrates are investigated using electronic absorption and fluorescence spectroscopy… read more here.
Keywords: henry reaction; cinchona alkaloid; reaction; spectroscopic study ... See more keywords
Synthesis, Biological Evaluation and Machine Learning Prediction Model for Fluorinated Cinchona Alkaloid-Based Derivatives as Cholinesterase Inhibitors
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DOI: 10.3390/ph15101214
Abstract: A series of 46 Cinchona alkaloid derivatives that differ in positions of fluorine atom(s) in the molecule were synthesized and tested as human acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors. All tested compounds reversibly inhibited AChE… read more here.
Keywords: cholinesterase inhibitors; bche; machine learning; ache ... See more keywords