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

Organic Letters, Год журнала: 2024, Номер 26(7), С. 1472 - 1477

Опубликована: Фев. 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).

Язык: Английский

---

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

Tetrahedron, Год журнала: 2024, Номер 156, С. 133939 - 133939

Опубликована: Март 9, 2024

Язык: Английский

---

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

Organic Letters, Год журнала: 2024, Номер unknown

Опубликована: Дек. 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.

Язык: Английский

---

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

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Апрель 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 %

Язык: Английский

---

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

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 366(8), С. 1756 - 1762

Опубликована: Фев. 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.

Язык: Английский

---

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, Год журнала: 2024, Номер 151, С. 155311 - 155311

Опубликована: Сен. 25, 2024

Язык: Английский

---