Synthesis of Functionalized Enamines (I): theα,β-Vicinal Bromoamine Compounds Converted intoα,β-Dehydroamino Derivatives Catalyzed by Thiourea in Mixture Solvent

An easy and efficient one-pot method for the synthesis of the functionalized enamines from the electron-deficient olefins has been developed. The electron-deficient olefins (including α,β-unsaturated esters and ketones) reacted with p-toluenesulfonamide (TsNH 2 )/N-bromosuccinimide (NBS) in CH 2 Cl 2 catalyzed by Al powder (5 mol%) at room temperature to generate corresponding α,β-vicinal bromoamines in the first step. Following those, the mixture products without separation can be direct smoothly converted into corresponding α-dehydroamino derivatives catalyzed by thiourea (50 mol%) and K 2 CO 3 (50 mol%) in mixture solvents [V(CH 2 Cl 2 ) ∶V(DMF)＝1∶1] at room temperature in good to excellent yields (up to 97%). 27 structurally different electron-deficient substrates were investigated. The results indicate that the protocol has applicability in a large scope of electron-deficient olefins. Based on the analysis of the all products in structure with 1 H NMR, it was revealed that the amino groups were linked at the α-position of carbonyl to the dehydroamino derivatives. This result indicates that the one-pot method has full regiospecificity.

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Section: 可能的反应机理unclassified

Synthesis of Functionalized Enamines (Ⅱ)：One-Pot Method for the Synthesis ofα-Dehydroamino from Electron-Deficient Olefins

闻化¹,

王英杰²,

刘德娥³

et al. 2014

Chin. J. Org. Chem.

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Bi(OTf)₃‐catalyed One‐pot Synthesis of α‐Halo‐β‐amino Ketones and Acyl Aziridines from 3‐Aryl Propargyl Alcohols

Duan

Guo

Yang

et al. 2021

Chemistry An Asian Journal

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A Bi(OTf)3‐catalyed reaction of 3‐aryl propargyl alcohols with sulfonamide and halogen source was firstly investigated, which provided a facile route for the synthesis of a large variety of α‐halo‐β‐amino ketones. The key intermediates, β‐amino ketones, were obtained through tandem Meyer‐Schuster rearrangement reaction of propargyl alcohols and intermolecular Michael addition of α, β‐unsaturated ketones and sulfonamide. Then the in situ generated α‐halo‐β‐amino ketones underwent the base‐promoted intramolecular cyclization to give diverse acyl aziridines in a one‐pot fashion. These transformations are reliable on a large scale. The high yields and convenient experimental operations make it a valuable method for the construction of α‐halo‐β‐amino ketones and acyl aziridine derivatives.

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One-pot synthesis of α,β-dehydroamino derivatives from β,β-dicyanostyrene with 1,3-dibromo-5,5-dimethylhydantoin promoted by mild base

Chen

Manfei

Wei

et al. 2016

Chem. Res. Chin. Univ.

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Synthesis of Functionalized Enamines (I): theα,β-Vicinal Bromoamine Compounds Converted intoα,β-Dehydroamino Derivatives Catalyzed by Thiourea in Mixture Solvent

Cited by 3 publications

References 5 publications

Synthesis of Functionalized Enamines (Ⅱ)：One-Pot Method for the Synthesis ofα-Dehydroamino from Electron-Deficient Olefins

Synthesis of Functionalized Enamines (Ⅱ)：One-Pot Method for the Synthesis ofα-Dehydroamino from Electron-Deficient Olefins

Bi(OTf)₃‐catalyed One‐pot Synthesis of α‐Halo‐β‐amino Ketones and Acyl Aziridines from 3‐Aryl Propargyl Alcohols

One-pot synthesis of α,β-dehydroamino derivatives from β,β-dicyanostyrene with 1,3-dibromo-5,5-dimethylhydantoin promoted by mild base

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Synthesis of Functionalized Enamines (I): theα,β-Vicinal Bromoamine Compounds Converted intoα,β-Dehydroamino Derivatives Catalyzed by Thiourea in Mixture Solvent

Cited by 3 publications

References 5 publications

Synthesis of Functionalized Enamines (Ⅱ)：One-Pot Method for the Synthesis ofα-Dehydroamino from Electron-Deficient Olefins

Synthesis of Functionalized Enamines (Ⅱ)：One-Pot Method for the Synthesis ofα-Dehydroamino from Electron-Deficient Olefins

Bi(OTf)3‐catalyed One‐pot Synthesis of α‐Halo‐β‐amino Ketones and Acyl Aziridines from 3‐Aryl Propargyl Alcohols

One-pot synthesis of α,β-dehydroamino derivatives from β,β-dicyanostyrene with 1,3-dibromo-5,5-dimethylhydantoin promoted by mild base

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Bi(OTf)₃‐catalyed One‐pot Synthesis of α‐Halo‐β‐amino Ketones and Acyl Aziridines from 3‐Aryl Propargyl Alcohols