Catalytic Stereoselective Multicomponent Reactions for the Synthesis of Spiro Derivatives: Recent Progress

European Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 2022(46)

Published: Nov. 16, 2022

Abstract Spiro derivatives are important scaffolding substances found in many natural products and pharmaceuticals. In the last decade, numerous new approaches based on multicomponent reactions have been explored for selective efficient development of spiro using various organocatalytic transition metal‐based catalytic systems. This Review discusses pioneering advances field stereoselective preparation derivatives. These include Michael cascade cyclization reactions, cycloadditions, diastereoselective miscellaneous synthesis spiro‐hetero/carbocycles. Advances decade made it possible to synthesize compounds with good excellent stereoselectivity under appropriate reaction conditions. However, achieving high regioselectivity several described remains a challenge. Organocatalysts transition‐metal‐based catalysts play crucial role this milestone. Proposed mechanisms supporting evidence highlighted Review. The progress is immense. expected that synthetic methods will soon be developed can widely used spiro‐heterocycles/carbocycles.

Language: Английский

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Transition-metal-free regioselective synthesis of spiro-oxazolidines through [3 + 2] annulation reactions of azadienes with haloalcohols

RSC Advances, Journal Year: 2025, Volume and Issue: 15(14), P. 10634 - 10638

Published: Jan. 1, 2025

The transition-metal-free regioselective [3 + 2] annulation of azadienes with haloalcohols for the preparation highly functionalized spiro-oxazolidines is experimentally simple, broad substrate scope, good yields, and excellent regioselectivity.

Language: Английский

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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 Asymmetric [3 + 2]-Annulations of γ-Sulfonamido/γ-Hydroxy-α,β-Unsaturated Ketones with CyclicN-Sulfimines: Synthesis of Chiral Polyheterotricyclic Imidazolidines and Oxazolidines

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 88(2), P. 1113 - 1127

Published: Dec. 29, 2022

The first organocatalytic asymmetric [3 + 2]-annulation of γ-sulfonamido-α,β-unsaturated ketones with cyclic N-sulfimines has been developed, and enantioenriched functionalized polyheterotricyclic imidazolidines were obtained in good yields excellent enantioselectivities. This approach was also extended to the γ-hydroxy-α,β-unsaturated ketones, affording oxazolidines. In addition, base-catalyzed 2]-annulations γ-sulfonamido/γ-hydroxy-α,β-unsaturated re-investigated under mild reaction conditions for synthesis racemic oxazolidines diastereoselectivities.

Language: Английский

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A One-Pot Cascade Strategy toward Organocatalytic Enantioselective Construction of Fused Benzimidazoles

Organic Letters, Journal Year: 2024, Volume and Issue: 26(21), P. 4502 - 4507

Published: May 20, 2024

Herein, we describe an asymmetric assembly of ortho-aromatic diamines and formyl tethered Michael acceptors forming chiral fused benzimidazoles. A cinchona-alkaloid-derived bifunctional squaramide catalyst enables the methodology through on-site dihydrobenzimidazole formation followed by aza-Michael addition/oxidation cascade. This protocol stands out for its excellent catalytic efficiency over background reaction mild conditions, making it more practical. Various acceptors, including enones, ester, thioester, were successful substrates in this study. Additionally, has demonstrated scalability successfully showcased postsynthetic transformations.

Language: Английский

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Organocatalytic asymmetric synthesis of oxazolidino spiropyrazolinonesvia N,O-acetalization/aza Michael addition domino reaction betweenN-Boc pyrazolinone ketimines and γ-hydroxyenones

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 21(11), P. 2361 - 2369

Published: Jan. 1, 2023

A squaramide-catalyzed asymmetric N,O-acetalization/aza Michael addition domino reaction between N-Boc ketimines derived from pyrazolin-5-ones and γ-hydroxyenones has been developed for the construction of pyrazolinone embedded spirooxazolidines. hydroquinine bifunctional squaramide catalyst was found to be most effective this cascade spiroannulation. This new protocol allows generation two stereocenters desired products are obtained in good yields with moderate diastereoselectivities (up 3.3 : 1 dr) high enantioselectivities >99% ee) a range substituted γ-hydroxyenones. The is amenable scale-up reaction.

Language: Английский

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Organocatalytic Asymmetric [4 + 2]-Cycloadditions of 2-Aminophenyl Enones with Isatin-Derived Ketimines: Diastereo- and Enantioselective Synthesis of Spirooxindole-Tetrahydroquinazolines

Organic Letters, Journal Year: 2023, Volume and Issue: 26(1), P. 252 - 257

Published: Dec. 26, 2023

A novel method for the enantioselective synthesis of spiro

Language: Английский

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Organocatalytic Synthesis of Furan-Embedded Styrene Atropisomers

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(18), P. 13358 - 13370

Published: Sept. 7, 2023

Herein, we report the first synthesis of furan-embedded styrene atropisomers via reaction between 1-(aryl-ethynyl)-naphthalen-2-ol and γ-hydroxyenone. The proceeds through in situ furan formation from derivatives were obtained moderate to good yields with high diastereoselectivities a catalytic amount PTSA. Few applications such as triazole cross-coupling reactions have been demonstrated. A preliminary asymmetric version was also reported.

Language: Английский

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Base‐catalyzed [3 + 2]/[4 + 2]‐annulations of cyclic N‐sulfimines with γ‐ and δ‐sulfonamido/hydroxy‐α,β‐unsaturated carbonyls: Stereoselective synthesis of imidazolidines, oxazolidines, hexahydropyrimidines, and 1,3‐oxazinanes

Bulletin of the Korean Chemical Society, Journal Year: 2023, Volume and Issue: 44(7), P. 619 - 628

Published: April 5, 2023

Abstract A highly efficient and straightforward synthetic methodology has been established for the preparation of imidazolidine derivatives through [3 + 2]‐annulation cyclic N ‐sulfimines. This reaction involves ‐sulfimines γ‐sulfonamido‐α,β‐unsaturated carbonyl compounds, with Cs 2 CO 3 serving as catalyst. The outcome is a diverse range remarkable yields stereoselectivities. In addition, [4 between δ‐sulfonamido‐α,β‐unsaturated catalyzed by Et N, successfully applied synthesis stereoselective hexahydropyrimidines. Furthermore, base‐catalyzed annulation γ‐ δ‐hydroxy‐α,β‐unsaturated compounds proven to be reliable method oxazolines 1,3‐oxazinanes.

Language: Английский

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Base‐Promoted [3+3]‐Cycloaddition of γ‐Hydroxy‐α,β‐unsaturated Carbonyls with N,N′‐Cyclic Azomethine Imines for Synthesizing Bicyclic Oxadiazines

European Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 2022(37)

Published: Sept. 14, 2022

Abstract A novel approach of [3+3]‐cycloaddition N,N′ ‐cyclic azomethine imines with γ‐hydroxy‐α,β‐unsaturated carbonyls was developed. Bicyclic oxadiazines were readily obtained in moderate to good yields from the reactions various ketones, including aromatic and aliphatic under mild conditions, demonstrating broad substrate scope.

Language: Английский

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