Organocatalytic Asymmetric Michael Reactions of Cyclic N-Sulfonylimines with Nitroalkenes or 2-Nitroallylic Acetates

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: March 25, 2025

A highly efficient enantioselective Michael addition of cyclic N-sulfonylimines with nitroalkenes has been developed, utilizing a bifunctional squaramide catalyst. This approach achieves remarkable results, delivering products high yields and outstanding stereoselectivities, reaching up to 97% yield, >20:1 dr, >99% ee. Furthermore, an asymmetric tandem reaction 2-nitroallylic acetates established. innovative methodology involves Michael/intramolecular aza-Michael cascade, leading the formation enantioenriched benzosultam-fused tricyclic compounds excellent stereoselectivities (up dr ee).

Language: Английский

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Base-Promoted [3+2]-Cycloaddition of N-Alkoxy-4-Oxo-Acrylamides with Isatins for Stereoselective Synthesis of Spirooxindole-2-Oxazolidinones

Published: Jan. 1, 2025

Language: Английский

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Base-promoted [3+2]-cycloaddition of N-alkoxy-4-oxo-acrylamides with isatins for stereoselective synthesis of spirooxindole-2-oxazolidinones

Tetrahedron Letters, Journal Year: 2025, Volume and Issue: unknown, P. 155624 - 155624

Published: May 1, 2025

Language: Английский

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2-((3R,9bS)-5,5-Dioxido-2,3-dihydro-9bH-benzo[4,5]isothiazolo[3,2-b]oxazol-3-yl)-1-phenylethan-1-one

Molbank, Journal Year: 2024, Volume and Issue: 2024(4), P. M1931 - M1931

Published: Dec. 5, 2024

A highly efficient method has been developed for preparing 2-((3R,9bS)-5,5-dioxido-2,3-dihydro-9bH-benzo[4,5]isothiazolo[3,2-b]oxazol-3-yl)-1-phenylethan-1-one. This enantioenriched title compound was obtained via an organocatalytic asymmetric [3+2]-cycloaddition of benzo[d]isothiazole 1,1-dioxide with (E)-4-hydroxy-1-phenylbut-2-en-1-one, using a bifunctional squaramide-based chiral catalyst. The reaction yielded 99% the product high enantioselectivity and diastereoselectivity (89:11 er >20:1 dr). structure newly synthesized confirmed by 1H-, 13C-NMR, IR mass spectral data.

Language: Английский

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Organocatalytic Enantioselective Synthesis of [5.7]-Fused ε-Sultam N,O-Heterocycles via (3 + 2)-Annulation of Seven-Membered Cyclic N-Sulfonylimines with γ-Hydroxy-α,β-Unsaturated Ketones

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(24), P. 18698 - 18706

Published: Dec. 10, 2024

A highly stereoselective protocol for the (3 + 2)-annulation of biphenyl-bridged seven-membered cyclic

Language: Английский

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