Asymmetric Organocatalytic [3 + 2]-Cycloaddition of N-Alkoxy-4-oxo-acrylamides with Isatin-Derived Ketimines: Access to Enantioselective Synthesis of Spirooxindole-imidazolidinones

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

Published: April 27, 2025

The spirooxindole framework is a privileged motif in numerous biologically significant natural products and has been demonstrated as crucial core scaffold variety of medicinally compounds. Herein, we achieved highly efficient enantioselective [3 + 2]-cycloaddition reaction N-alkoxy-4-oxo-acrylamides with isatin-derived ketimines. This method enabled the precise synthesis chiral spirooxindole-imidazolidinone derivatives, which are notable for their intricate structures presence quaternary centers. Our approach utilized an organocatalytic strategy hydrogen-bonding bifunctional squaramide-based catalyst. impressive results, achieving high yields exceptional enantioselectivities >99% ee majority substrates, even when employing only 2 mol %

Language: Английский

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Organocatalytic Enantioselective Synthesis of Polycyclic Benzosultams from 2-Amino-β-nitrostyrenes with Cyclic N-Sulfonyl Ketimines

Organic Letters, Journal Year: 2024, Volume and Issue: 26(7), P. 1472 - 1477

Published: Feb. 13, 2024

A highly efficient enantioselective [4 + 2] cycloaddition of 2-amino-β-nitrostyrenes with cyclic N-sulfonyl ketimines has been developed. This reaction utilizes an organocatalytic approach, employing a multiple-hydrogen-bonding bifunctional squaramide-based catalyst. The process allows for the precise synthesis chiral polycyclic benzosultams, showcasing intricate structures that incorporate quaternary centers. Noteworthy outcomes this method include high yields excellent enantioselectivities and diastereoselectivities (up to 97% yield, 96% ee, >20:1 dr).

Language: Английский

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Mn(III)-based oxidative cyclization of 2,2′-(methylene)bis(3-hydroxycyclopent-2-en-1-one)s. Formation of angular spirodihydrofurans through dispirocyclopropanes

Tetrahedron, Journal Year: 2024, Volume and Issue: 156, P. 133939 - 133939

Published: March 9, 2024

Language: Английский

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Palladium-Catalyzed Strain-Enabled [2π + 2σ] Cycloadditions of Vinyl Bicyclo[1.1.0]butanes with Methyleneindolinones

Organic Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 26, 2024

A palladium-catalyzed [2π + 2σ] cycloaddition of vinyl bicyclo[1.1.0]butanes with methyleneindolinones has been developed. The reaction enables the construction spirobicyclo[2.1.1]hexanes bearing an all-carbon quaternary center in moderate to good yields excellent diastereoselectivities. This method features a broad substrate scope functional group compatibility. practical utility this protocol was further demonstrated by gram-scale synthesis and postsynthetic transformations desired product.

Language: Английский

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Asymmetric Synthesis of 3,4‐Dihydroquinolin‐2‐ones via Organocatalytic [4+2]‐Cyclization of 2‐Amino‐β‐nitrostyrenes with Azlactones

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(8), P. 1756 - 1762

Published: Feb. 29, 2024

Abstract Dihydroquinolin‐2‐ones, recognized for their bioactive properties, feature a six‐membered structure with nitrogen‐containing heterocycles. A method has been developed synthesizing enantioenriched 3,4‐dihydroquinoline‐2‐one derivatives. This approach utilizes an asymmetric [4+2]‐cyclization process, combining 2‐amino‐β‐nitrostyrenes azlactones, and is facilitated by bifunctional squaramide‐based organocatalyst. process enabled the creation of chiral 3,4‐dihydroquinoline‐2‐ones complex structures, including tetrasubstituted carbon stereocenters, delivering corresponding products in 26–95% yield diastereomeric ratio 1.2:1–19:1 52–97 ee.

Language: Английский

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A quinine squaramide catalyzed enantioselective [4 + 2] cycloaddition between ortho-hydroxyphenyl para-quinone methide and γ-butenolides for preparation of chiral 3, 4-dihydrocoumarins

Tetrahedron Letters, Journal Year: 2024, Volume and Issue: 151, P. 155311 - 155311

Published: Sept. 25, 2024

Language: Английский

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