Catalytic enantioselective [3+2] and [4+2]-annulation of cyclic N-sulfonyl ketimines with γ- or δ-hydroxy-α,β-unsaturated ketones

Chemical Communications, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

A highly efficient asymmetric [3+2] and [4+2]-annulation of cyclic N -sulfonyl ketimines with γ- or δ-hydroxy-α,β-unsaturated ketones has been developed.

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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Synthesis of Polycyclic Imidazolidinones via Cascade [3 + 2]-Annulation of β-Oxo-acrylamides with Cyclic N-Sulfonyl Imines

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(22), P. 15805 - 15816

Published: Oct. 31, 2023

An Et3N-catalyzed cascade [3 + 2]-annulation of β-oxo-acrylamides with cyclic N-sulfonyl ketimines or sulfamate-derived imines is developed under mild reaction conditions, which provides a concise and efficient route to access valuable sultam- sulfamidate-fused imidazolidinone derivatives in good excellent yields (80–95% yields) diastereoselectivities (>20:1 drs). The current protocol features atom economy, transition-metal-free process, broad functional group tolerance. Moreover, the asymmetric variant 2]-cycloaddition was achieved presence diphenylethanediamine quinine-based bifunctional squaramide organocatalysts C-1 C-11, giving corresponding chiral polycyclic imidazolidinones 68–90% 25–94% ees >20:1 drs all cases.

Language: Английский

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Improvement of Asymmetric Reactions via Remote Electronic Tuning of N‐Heterocyclic Carbene Catalysts

ChemCatChem, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 1, 2024

Abstract Aminoindanol‐derived N‐heterocyclic carbene catalysts have been widely used to achieve highly enantioselective reactions. Recently, substitution at the indane moiety of has found a great impact on outcome some reactions, even though substituted position is distant from catalytic center. Especially, introduction an electron‐withdrawing group improves yield and enantioselectivity. This review provides overview recent reports improvement N‐heterocyclic‐carbene‐catalyzed asymmetric reactions by introducing remote substituents.

Language: Английский

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[1,5]-Oxy/Thio/Azole Sigmatropic Rearrangement versus Indolyl-Spirocyclization: Tandem Reactions of 2-Azidobenzoate with Isocyanides for Accessing Quinazolin-4(3H)-ones

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

Published: Nov. 25, 2024

A general protocol for the synthesis of a variety functionalized quinazolinones has been developed through sequential Pd-catalyzed coupling/1,5-alkyloxy/thio/azole shift/6π electrocyclization reaction isocyanides and 2-carbonylaryl azides. When 3-(2-isocyanoethyl)indoles were utilized, an unusual competitive between [1,5]-shift indole-spirocyclization was observed, which renders modular spiroindolenine-3,3'-pyrrolo[2,1-

Language: Английский

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