Ring-Opening Cyclization (ROC) of Aziridines with Propargyl Alcohols: Synthesis of 3,4-Dihydro-2H-1,4-oxazines

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(7), P. 4504 - 4518

Published: March 27, 2023

Activated aziridines react with propargyl alcohols in the presence of Zn(OTf)2 as Lewis acid catalyst following an SN2-type ring-opening mechanism to furnish corresponding amino ether derivatives. Those ethers further undergo intramolecular hydroamination via 6-exo-dig cyclization and tetrabutylammonium triflate salt additive under one-pot two-step reaction conditions. However, for nonracemic examples, steps were conducted two-pot The works well without any additional solvents. final 3,4-dihydro-2H-1,4-oxazine products obtained 13 84% yield 78 98% enantiomeric excess (for examples).

Language: Английский

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Regioselective Brønsted Acid Catalyzed Ring Opening of Aziridines by Phenols and Thiophenols; A Gateway to Access Functionalized Indolines, Indoles, Benzothiazines, Dihydrobenzo-thiazines, Benzo-oxazines and Benzochromenes

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(27), P. 5653 - 5664

Published: Jan. 1, 2024

A TfOH-catalyzed regioselective ring opening of aziridines by phenols and thiophenols have been reported. Further synthetic transformations lead to access a range useful heterocycles.

Language: Английский

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Recent Advances in the Synthesis of Imidazolines (2009–2020)

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 362(20), P. 4189 - 4225

Published: July 27, 2020

Abstract Imidazoline is an important class of compounds found in numerous natural and pharmaceutical products. The are also used as intermediate the synthesis organic molecules. Moreover, chiral imidazolines widely utilized organocatalysts to synthesize various synthetic compounds. In past decade, there was increase interest developing new methods these imidazoline analogs. Both modification previously established development carried out significantly. This review article highlights progress scaffolds last few years (2009‐present). described proposed mechanism illustrated many reports. magnified image

Language: Английский

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Synthesis of Diversely Substituted Imidazolidines via [3+2] Cycloaddition of 1,3,5‐Triazinanes with Donor‐Acceptor Aziridines and Their Anti‐Tumor Activity

Advanced Synthesis & Catalysis, Journal Year: 2021, Volume and Issue: 363(10), P. 2619 - 2624

Published: Feb. 26, 2021

Abstract A Y(OTf) 3 ‐catalyzed [3+2] cycloaddition of 1,3,5‐triazinanes with donor‐acceptor aziridines has been developed, accessing diversely substituted imidazolidines high efficiency. Mechanistic investigations support the formation through an S N 1‐like pathway. Furthermore, these exhibit promising anti‐tumor activity against a series human cancer cell lines. magnified image

Language: Английский

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Cationic Divalent Metal Sites (M = Mn, Fe, Co) Operating as Both Nitrene-Transfer Agents and Lewis Acids toward Mediating the Synthesis of Three- and Five-MemberedN-Heterocycles

Inorganic Chemistry, Journal Year: 2023, Volume and Issue: 62(27), P. 10743 - 10761

Published: June 23, 2023

The tripodal compounds [(TMG

Language: Английский

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Enantioselective [3+2] Cycloaddition of Donor‐Acceptor Aziridines and Imines to Construct 2,5‐trans‐Imidazolidines

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(18)

Published: Jan. 5, 2023

An enantioselective [3+2] cycloaddition of donor-acceptor aziridines with N-aryl protected imines was developed a Ni(ClO4 )2 ⋅ 6H2 O/N,N'-dioxide catalyst system, providing broad range chiral trans-substituted imidazolidine compounds good yields and excellent enantioselectivities (up to 99 % yield, up 98 ee). Control experiments indicated that the products could offer diastereoselectivities control Ni(II)-N,N'-dioxide complex interaction substrates. The possible catalytic process proposed rationalize stereocontrol.

Language: Английский

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Recent Advances in Cycloaddition Reactions of Donor-Acceptor Aziridines via Carbon-Carbon Bond Cleavage

Chinese Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 43(9), P. 3078 - 3078

Published: Jan. 1, 2023

There are two different ring-opening modes of aziridines: aziridines via carbon-nitrogen bond cleavage, and carbon-carbon cleavage.Among them, the reaction cleavage has been reported in many reviews.The cycloaddition reactions donor-acceptor (D-A) recent 20 years mainly summarized.Under some proper catalysts, D-A yield azomethine ylides, which can undergo [3＋n] with aldehydes, imines, alkenes, alkynes, indoles etc.

Language: Английский

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2‐Amino‐5‐(cyanomethylsulfanyl)‐1H‐pyrroles from Propargylamines, Isothiocyanates, and Bromoacetonitrile by One‐Pot Synthetic Protocol

ChemistrySelect, Journal Year: 2020, Volume and Issue: 5(19), P. 5726 - 5731

Published: May 18, 2020

Abstract Tertiary propargylamines (such as N , ‐dialkylpropargylamines, ‐propargylpyrrolidine, ‐piperidine, and ‐morpholine), isothiocyanates, bromoacetonitrile have been shown to be readily available building blocks for the highly selective one‐pot construction of rare‐functionalized pyrroles, namely so far inaccessible 1‐substituted 2‐amino‐5‐(cyanomethylsulfanyl)‐1 H ‐pyrroles, in up 92 % yield. This efficient operationally simple approach includes initial formation lithium but‐2‐ynimidothioate (adduct monolithiated propargylamine isothiocyanate), its transformation into potassium buta‐2,3‐dienimidothioate under action t ‐BuOK/DMSO system (through acetylene‐allene isomerization exchange by cations), intramolecular cyclization thienylamide (at ≤15 °C), followed re‐cyclization pyrrolylsulfide at a higher temperature (45–60 final S‐alkylation latter with bromoacetonitrile. The total reaction time is 45–60 min.

Language: Английский

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Visible Light Organo‐Photocatalytic Synthesis of 3‐Imidazolines

European Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 2022(44)

Published: Nov. 25, 2022

Abstract An efficient regioselective synthesis of tetrasubstituted 3‐imidazolines under organo‐photocatalytic conditions has been developed through formal [3+2]‐cycloaddition between 2 H ‐azirines and N ‐tosyl benzylidene imines. The products were isolated in high yields as a separable mixture diastereoisomers most the cases. mild reaction employing an organic dye photocatalyst, excellent functional group tolerance, regioselectivity are notable features current protocol.

Language: Английский

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TfOH-Catalyzed Facile Access for One-Pot Synthesis of β-Acylamino Ketones by Avoiding the Usage of Acetyl Chloride

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

Published: March 28, 2024

Abstract We have developed a TfOH-catalyzed, highly efficient protocol for the synthesis of biologically active β-acylamino ketones from aldehyde, ketone, and nitrile by avoiding use acetyl chloride. The reaction proceeds through sequential aldol followed nucleophilic attack hydrolysis in one pot. attractive features this tandem process are mild conditions, high atom economy, broad substrate scope with 51–87% yield, gram-scale reaction, ease operation.

Language: Английский

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