Enantioselective synthesis of 2-amino-4H-chromene derivatives with antifungal activities on phytopathogenic fungi

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(13), P. 3692 - 3699

Published: Jan. 1, 2024

An Ir-catalyzed enantioselective cascade allylation/cyclization reaction of 2-(1-hydroxyallyl)phenols was developed, affording antifungal 2-amino-4 H -chromene derivatives with good to excellent enantioselectivities.

Language: Английский

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Copper Catalyzed [3+2] Annulation Reaction of Exocyclic Sulfonyl Enamides for the Synthesis of N,O‐Spiroketal and Spiroketal

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(44)

Published: June 1, 2024

A copper-catalyzed [3+2] annulation reaction of exocyclic enamines/enol ethers with 1,4-benzoquinone esters has been developed, providing facile access to N,O-spiroketals and spiroketals under mild conditions broad substrate scope (26 examples, 71-94 % yields). Gram scale synthesis chemical transformations demonstrated that this method is potentially useful in the natural products drugs containing a N,O- spiroketal moiety. The chiral N,O-spiroketal could be obtained 98 ee after recrystallization, when SaBOX ligand was employed.

Language: Английский

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Gold/Iridium Catalyzed Alkynylamide Cyclization/Asymmetric Allylic Benzylation Cascade Reaction^★

Acta Chimica Sinica, Journal Year: 2023, Volume and Issue: 81(5), P. 431 - 431

Published: Jan. 1, 2023

Asymmetric allylic substitution reactions involving benzyl nucleophilic reagents can rapidly construct chiral molecules containing fragments, which has attracted widespread attention from organic chemists.Formal asymmetric benzylation have been achieved by utilizing methylene oxazole as an equivalent of nucleophile.However, the development highly efficient remains a great challenge mainly due to poor stability and synthetic difficulty oxazole.In this work, we developed gold-and iridiumcatalyzed alkynylamide cyclization/asymmetric cascade reactions.In presence gold-carbene complex (Au1) combination [Ir(cod)Cl]2 (Sa)-Carreira ligand, wide range enantioenriched derivatives, bearing benzylic stereogenic center, were obtained in 49%～87% yields with 98%～＞99% ee.A general procedure is described following: To dried Schlenk tube added (5.4 mg, 0.008 mmol, 4 mol%), (Sa)-L1 (16.2 0.032 16 mol%) 1,2-dichloroethane (1 mL) under argon atmosphere.The mixture was stirred at room temperature for 15 minutes give iridium solution.Under atmosphere, (0.2 1.0 equiv.),allyl alcohol (0.4 2.0 equiv.),Au1 (0.02 12.4 10 Fe(OTf)2 70.6 equiv.)and 3 Å molecular sieves (80.0 mg) another dry tube, then above-prepared catalyst added.The reaction 40 ℃ until starting materials consumed (monitored thin layer chromatography, TLC).The quenched water (5 mL), extracted dichloromethane mL×3).The combined layers over anhydrous Na2SO4, filtered, concentrated vacuo afford crude product.The residue purified column chromatography (V(petroleum ether)/V(ethyl acetate)＝15/1 or 10/1) product 3.

Language: Английский

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Synthesis, Crystal Structure Analysis and DFT Studies of Two Benzospirocyclic Ketones

Journal of Structural Chemistry, Journal Year: 2024, Volume and Issue: 65(4), P. 798 - 809

Published: April 1, 2024

Language: Английский

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Ir/Brønsted acid dual-catalyzed asymmetric synthesis of bisbenzannulated spiroketals and spiroaminals from isochroman ketals

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(20), P. 5831 - 5840

Published: Jan. 1, 2024

An Ir/Brønsted acid dual-catalyzed asymmetric cascade reaction of 2-(1-hydroxyallyl)phenols with isochroman ketals was developed, affording antifungal spiroketals high enantioselectivities.

Language: Английский

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