Synthesis of Carbamoyl Fluorides via a Selective Fluorinative Beckmann Fragmentation

Organic Letters, Journal Year: 2021, Volume and Issue: 23(14), P. 5394 - 5399

Published: July 1, 2021

A fluorinative Beckmann fragmentation of α-oximinoamides was devised to provide synthetically useful carbamoyl fluorides. High selectivity for over a potentially competing rearrangement observed. This protocol has distinct mechanism and thus different substrate scope compared with other synthetic methods. α-Oximinoamides derived from the readily available secondary amines, lactams, or isatins were converted into structurally diverse

Language: Английский

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Substrate-Controlled Regioselectivity Switchable [3 + 2] Annulations To Access Spirooxindole Skeletons

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(12), P. 8158 - 8169

Published: June 8, 2022

The additive-free [3 + 2] annulation from isatins, amino acids with 2-styrylbenzoxazoles, was described, providing a series of functional and structurally complex 3,3'-pyrrolidinyl-spirooxindole derivatives containing four contiguous two quaternary stereogenic centers in high yields (up to 95%) excellent diastereoselectivities >25:1 dr). Interestingly, the reaction exhibits switchable regioselectivity depending on substrate acids. With proline or thioproline as substrate, afforded α-regioselective spirooxindole skeletons. In contrast, when piperidine acid is provided γ-regioselective

Language: Английский

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Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

Beilstein Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 19, P. 1234 - 1242

Published: Aug. 22, 2023

A convenient synthetic procedure for the construction of novel dispirooxindole motifs was successfully developed by base-promoted three-component reaction ammonium acetate, isatins and in situ-generated 3-isatyl-1,4-dicarbonyl compounds. The piperidine-promoted dimedone adducts 3-ethoxycarbonylmethyleneoxindoles afforded mutlifunctionalized dispiro[indoline-3,2'-quinoline-3',3''-indoline] derivatives good yields with high diastereoselectivity. On other hand, a similar 3-phenacylideneoxindoles unique dispiro[indoline-3,2'-pyrrole-3',3''-indoline] cyclohexanedione substituent. plausible mechanism is proposed to explain formation different spirooxindoles.

Language: Английский

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Dynamic Kinetic Asymmetric Transformation of Racemic Diastereomers: Diastereo‐ and Enantioconvergent Michael–Henry Reactions to Afford Spirooxindoles Bearing Furan‐Fused Rings

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(39), P. 21256 - 21260

Published: July 8, 2021

Dynamic kinetic asymmetric transformation (DYKAT) reactions of racemic diastereomer mixtures that afford the products as essentially single diastereomers with high enantioselectivities are described. We demonstrated DYKAT in diastereo- and enantioselective synthesis spirooxindoles bearing furan-fused rings. The starting materials DYKAT, dihydrobenzofuranone derivatives, were synthesized mixtures, these transformed to spirooxindole derivatives yields through Michael-Henry cascade nitrostyrenes under organocatalytic conditions. In reactions, regardless stereochemistry materials, all four isomers enantioselectivities, new chiral centers created.

Language: Английский

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Substrate-Controlled Diastereo- and Enantiodivergent Synthesis of Bis-Spirocyclopropyloxindoles from Available Isatin as a Single Starting Material

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(9), P. 5254 - 5274

Published: April 21, 2023

The first diastereo- and enantiodivergent asymmetric synthesis of new bis-spirocyclopropyloxindole scaffolds has been accomplished from the readily available isatin as a single starting material. Four rel-(1R,2R,3R), rel-(1S,2S,3R), rel-(1R,2R,3S), rel-(1S,2S,3S) configurations desired products were constructed in excellent enantiopurity via simple switch substrates using chiral auxiliary-controlled method. absolute configuration cycloadducts with three contiguous quaternary/tertiary stereogenic centers was confirmed through X-ray diffraction analysis. A facile versatile precursor 3-chlorooxindoles also introduced.

Language: Английский

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Enantioselective Desymmetrization of Curcumins with 3‐Olefinic Oxindoles for the Synthesis of Spirocyclohexanoneoxindoles

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 26(15)

Published: Feb. 24, 2023

Abstract An enantioselective desymmetrization of curcumins with 3‐olefinic oxindoles involving a cascade double‐Michael addition strategy provides direct access to spirocyclohexanone‐oxindoles complete regio‐ and diastereoselectivities excellent enantioselectivities, besides good yields. The products possess three contiguous chiral centers multiple reactive functionalities. observed selectivities were rationalized by transitions state energy calculations at B3LYP//6‐31g(d) level DFT.

Language: Английский

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Diastereoselectivity‐Switchable Gold‐Catalyzed Formal [3+2]‐Cycloadditions of N‐2,2,2‐Trifluoroethylisatin Ketimines with Yne−Enones

Chemistry - An Asian Journal, Journal Year: 2021, Volume and Issue: 16(17), P. 2435 - 2438

Published: Aug. 1, 2021

Abstract The unexpected gold‐catalyzed formal [3+2]‐cycloaddition of N ‐2,2,2‐trifluoroethylisatin ketimines with 2‐(1‐Alkynyl)‐2‐alken‐1‐ones is reported. Both diastereomers the corresponding cycloadducts were formed in moderate to excellent yields diastereoselectivities by switching catalytic system from mono‐gold gold/silver bimetallic system. practicality this protocol demonstrated scale‐up reaction and transformations cycloadduct.

Language: Английский

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Base Promoted Three‐component Reaction for Efficient Construction of Spiro[indoline‐3,3′‐quinoline]‐2,5′‐dione

ChemistrySelect, Journal Year: 2023, Volume and Issue: 8(37)

Published: Oct. 2, 2023

Abstract A convenient synthetic protocol for the construction of spiro[indoline‐3,3′‐quinoline]‐2,5′‐dione motifs was successfully developed by base promoted one‐pot three‐component reaction. In presence piperidine, reaction ammonium acetate, aromatic aldehydes and in situ generated 3‐isatyl 1,4‐dicarbonyl compounds, which were derived from mediated addition dimedone to 3‐methyleneoxindoles, resulted two diastereoisomers derivatives good yields with diastereoselectivity. The stereochemistry clearly elucidated isolation diastereomers determination several single crystal structures.

Language: Английский

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Dynamic Kinetic Asymmetric Transformation of Racemic Diastereomers: Diastereo‐ and Enantioconvergent Michael–Henry Reactions to Afford Spirooxindoles Bearing Furan‐Fused Rings

Angewandte Chemie, Journal Year: 2021, Volume and Issue: 133(39), P. 21426 - 21430

Published: July 8, 2021

Abstract Dynamic kinetic asymmetric transformation (DYKAT) reactions of racemic diastereomer mixtures that afford the products as essentially single diastereomers with high enantioselectivities are described. We demonstrated DYKAT in diastereo‐ and enantioselective synthesis spirooxindoles bearing furan‐fused rings. The starting materials DYKAT, dihydrobenzofuranone derivatives, were synthesized mixtures, these transformed to spirooxindole derivatives yields through Michael–Henry cascade nitrostyrenes under organocatalytic conditions. In reactions, regardless stereochemistry materials, all four isomers enantioselectivities, new chiral centers created.

Language: Английский

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Enantioselective C–C, C–halogen and C–H bond forming reactions promoted by organocatalysts based on non-proteinogenic α-amino acid derivatives

Advances in catalysis, Journal Year: 2023, Volume and Issue: unknown, P. 143 - 210

Published: Jan. 1, 2023

Language: Английский

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