Results 181 to 190 of about 10,800 (238)
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Chiral phosphoric acids: a chiral lobby for enantioselective C–H activation
Chemical Communications, 2023Chiral phosphoric acids can interact in different ways with the substrate to induce chirality into the system. This review summarizes the use of chiral phosphoric acids in the exciting field of enantioselective C–H activation.
null Sumit +2 more
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Chiral Phosphoric-Acid-Catalyzed Cascade Prins Cyclization
Organic Letters, 2019Asymmetric Prins cyclization of in situ generated quinone methides and o-aminobenzaldehyde has been developed with chiral phosphoric acid as an efficient catalyst. This unconventional method provides a facile access to diverse functionalized trans-fused pyrano-/furo-tetrahydroquinoline derivatives in excellent yield and with excellent diastereo- and ...
Huai-Ri Sun +6 more
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Reactions of Chiral Phosphorous Acid Diamides
Phosphorus, Sulfur, and Silicon and the Related Elements, 1993Abstract Chiral phosphorous acid diamides were prepared from chiral C2 diamines via the sequential addition of PCl3 and H2O. Alternatively, addition of PCI3 and hydrogen sulfide yieded the analogous thiophosphorous acid diamides. Deprotonation of the phosphorous acids under a variety of conditions gave the anions which reacted smoothly with alkyl ...
Vincent Blazis +3 more
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Chiral Phosphoric Acid Catalyzed Stereoselective Spiroketalizations
Synlett, 2013The spiroketal functionality is an important structural motif present in numerous natural products. The synthesis of chiral spiroketals is typically achieved under equilibrating conditions and only few asymmetric approaches are known. We have demonstrated that chiral phosphoric acids (CPAs) could serve as effective catalysts for enantioselective ...
Pavel Nagorny +2 more
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Chiral Phosphoric Acid-Catalyzed Enantioselective and Diastereoselective Spiroketalizations
Journal of the American Chemical Society, 2012Catalytic enantioselective and diastereoselective spiroketalizations with BINOL-derived chiral phosphoric acids are reported. The chiral catalyst can override the inherent preference for the formation of thermodynamic spiroketals, and highly selective formation of nonthermodynamic spiroketals could be achieved under the reaction conditions.
Zhankui, Sun +3 more
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Chiral phosphoric acid catalysis: from numbers to insights
Chemical Society Reviews, 2018Chiral phosphoric acids (CPAs) have emerged as powerful organocatalysts for asymmetric reactions, and applications of computational quantum chemistry have revealed important insights into the activity and selectivity of these catalysts.
Rajat Maji +2 more
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Synthesis of chiral amino cyclic phosphoric acids
Wuhan University Journal of Natural Sciences, 2000Chiral amino cyclic phosphoric acids, 5-amino-2-hydroxy-4-(4-nitrophenyl)-1,3,2-dioxaphosphorinane 2-oxide and 2-hydroxy-4-(4-methylsulfonylphenyl)-5-phthalimido-1,3,2-dioxaphos phorinane 2-oxide are synthesized in good over yields (64.2% and 72.8% respectively) from 2-amino-1-aryl-1,3-propanediols.
Zhang Zhan +5 more
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Angewandte Chemie, 2020
AbstractA new chiral Brønsted acid, generated in situ from a chiral phosphoric acid boron (CPAB) complex and water, was successfully applied to asymmetric indole reduction. This “designer acid catalyst”, which is more acidic than TsOH as suggested by DFT calculations, allows the unprecedented direct asymmetric reduction of C2‐aryl‐substituted N ...
Kai Yang +11 more
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AbstractA new chiral Brønsted acid, generated in situ from a chiral phosphoric acid boron (CPAB) complex and water, was successfully applied to asymmetric indole reduction. This “designer acid catalyst”, which is more acidic than TsOH as suggested by DFT calculations, allows the unprecedented direct asymmetric reduction of C2‐aryl‐substituted N ...
Kai Yang +11 more
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Asymmetric binary acid catalysis: chiral phosphoric acid as dual ligand and acid
Chem. Commun., 2013Recently, chiral Brønsted acids as dual ligand and acid catalysts in the context of metal catalysis have been developed. Such binary catalytic systems synergistically integrate chiral Brønsted acids and metal catalysts as a result of their weakly coordinating behaviors.
Jian, Lv, Sanzhong, Luo
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The Chemical Record, 2023
AbstractIndoles are one of the most ubiquitous subclass of N‐heterocycles and are increasingly incorporated to design new axially chiral scaffolds. The rich profile of reactivity and N−H functionality allow chemical derivatization for enhanced medicinal, material and catalytic properties.
Jun, Kee Cheng, Bin, Tan
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AbstractIndoles are one of the most ubiquitous subclass of N‐heterocycles and are increasingly incorporated to design new axially chiral scaffolds. The rich profile of reactivity and N−H functionality allow chemical derivatization for enhanced medicinal, material and catalytic properties.
Jun, Kee Cheng, Bin, Tan
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