Palladium-Catalyzed Aerobic Oxidative Spirocyclization of Alkyl Amides with Maleimides via β-C(sp³)–H Activation

Organic Letters, Год журнала: 2023, Номер 25(34), С. 6305 - 6310

Опубликована: Авг. 22, 2023

An efficient method for the synthesis of bicyclic spirodiamine molecules via β-C(sp3)–H bond activation aliphatic amides, followed by cyclization with maleimides, has been developed. The reaction proceeds through an amide-directed alkyl amides and subsequent maleimides. methodology is highly compatible a wide variety Amides derived from biologically active fatty acids were also found to be protocol. A palladacycle was synthesized intermediate in this reaction. plausible mechanism proposed account spirocyclization.

Язык: Английский

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Palladium-Catalysed Spiro-Cyclisation of Substituted Amino Acids with Maleimides via γ-C(sp³)–H Bond Activation

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Апрель 1, 2025

Achieving the site-selective functionalization of unactivated C(sp3)-H bonds remains a major challenge in organic synthesis. Herein, we report an efficient method for synthesis spiro pyrrolidine molecules via γ-C(sp3)-H bond activation substituted amino acids. A variety acid and alcohol derivatives, as well dipeptides, were functionalized using this method. Also, spirocyclization optically active substrates provided potential route preparing separable diastereomers pure enantiomeric form. Moreover, some mechanistic insights have been conducted to propose feasible reaction mechanism present reaction.

Язык: Английский

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Multi-Component Syntheses of Spiro[furan-2,3′-indoline]-3-carboxylate Derivatives Using Ionic Liquid Catalysts

Molecules, Год журнала: 2024, Номер 29(6), С. 1223 - 1223

Опубликована: Март 8, 2024

Two previously described Brønsted acidic ionic liquids, 3,3′-(1,6-hexanediyl)bis(1-methyl)-1H-imidazolium hydrogen sulfate (Cat1) and 1,1′-(1,6-hexanediyl)bis(pyridinium) (Cat2), were used as catalysts for the preparation of spiro[furan-2,3′-indoline]-3-carboxylate derivatives via a three-component reaction anilines, isatins (N-alkyl-indoline-2,3-diones), diethyl acetylenedicarboxylate, in high yields. The use ultrasonic (US) irradiation led to targeted products (1a–15a) yields ranging from 80% 98%. Under same conditions, sulfuric acid acetic Brønstedt catalyst did not yield desired benchmark product 1a.

Язык: Английский

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NHC-Catalyzed Reaction of Aldehydes for C(sp2)–O Bond Formation

Catalysts, Год журнала: 2024, Номер 14(4), С. 219 - 219

Опубликована: Март 22, 2024

In the past few decades, N-heterocyclic carbenes (NHCs) have opened new field of organocatalysis in synthetic organic chemistry. This review highlights dramatic progress NHC-catalyzed C–O bond formation based on activation aldehyde C(sp2)–H bonds. The oxidative and redox transformations for synthesis various molecules with structural diversity complexity are summarized. Furthermore, methods strategies NHC catalysis emerging continuously; thus, cooperative Brønsted acid, hydrogen-bonding catalyst, transition-metal photocatalyst also described.

Язык: Английский

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Mechanisms and Origins of Stereoselectivity in NHC-Catalyzed Oxidative Reaction of Enals and Pyrroles: A Density Functional Theory Study

Physical Chemistry Chemical Physics, Год журнала: 2024, Номер unknown

Опубликована: Янв. 1, 2024

The mechanism, and chemo- stereoselectivity in the NHC-catalyzed oxidative reaction of enals pyrroles.

Язык: Английский

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Substrate-Controlled Regioselective Cascade Reactions of Deconjugated Butenolides and Cinnamaldehydes: Access to Structurally Diverse Spirobutenolides

Organic Letters, Год журнала: 2024, Номер unknown

Опубликована: Окт. 3, 2024

Two different cascade pathways to access spirobutenolides were achieved based on the substrate-controlled regioselectivity of deconjugated butenolides. A new class functional butenolides was designed and exhibited superior γ-regioselectivity in vinylogous Michael/Michael reactions with cinnamaldehydes. The aryl-substituted cinnamaldehydes underwent a Michael/Michael/aldol/dehydration process induced by double α-regioselectivities. Both conjugated could be obtained good yields excellent enantioselectivities.

Язык: Английский

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Five-membered ring systems: With more than 1 N atom

Progress in heterocyclic chemistry, Год журнала: 2024, Номер unknown, С. 211 - 257

Опубликована: Янв. 1, 2024

Язык: Английский

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