Benefits of a Dual Chemical and Physical Activation: Direct aza-Michael Addition of Anilines Promoted by Solvent Effect under High Pressure

Fedotova, Alena; Crousse, Benoı̂t; Chataigner, Isabelle; Maddaluno, Jacques; Rulev, Alexander Yu.; Legros, Julien

doi:10.1021/acs.joc.5b01756

Cited by 38 publications

(28 citation statements)

References 47 publications

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“…However, the thermodynamic stabilization gained from formation of the intramolecular hydrogen bond shifts the equilibrium towards the Z-isomer over time. The equilibrium proportion of the E configuration in acetone-d 6 The reaction with 2a was performed using N-methylaniline, 1m to eliminate the intramolecular hydrogen bond and assess the resulting configurational and conformational effects. The reaction proceeded with equal efficacy to the activated anilines, and FTIR monitoring showed that the carbonyl stretch of enaminone 3m…”

Section: Resultsmentioning

confidence: 99%

Conjugate Addition of 3-Buytn-2-one to Anilines in Ethanol: Alkene Geometric Insights through In Situ FTIR Monitoring

et al. 2016

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Publisher's copyright statement:This document is the Accepted Manuscript version of a Published Work that appeared in nal form in The Journal of Organic Chemistry, copyright c American Chemical Society after peer review and technical editing by the publisher. To access the nal edited and published work see http://dx.doi.org/10.1021/acs.joc.6b01110. Additional information:Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractA convenient, mild and effective conjugate addition of 3-butyn-2-one to a variety of anilines in ethanol is reported. The reaction was monitored and characterized through in situ FTIR, and the dynamics of the facile E/Z alkene geometry interconversion of the resultant aniline-derived enaminones was explored through NMR, FTIR and Xray crystallography. A straightforward purification protocol that employs direct Kugelrohr distillation was identified and the method was further extended to other amines and ynones, allowing rapid access to these interesting compounds.

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Section: Resultsmentioning

confidence: 99%

Conjugate Addition of 3-Buytn-2-one to Anilines in Ethanol: Alkene Geometric Insights through In Situ FTIR Monitoring

et al. 2016

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“…The results are shown in Figure . In all cases, hexafluoroisopropyl esters of semistabilized allyl‐ and benzylsulfonates gave better yields than trifluoroethyl sulfonates . It is worth stressing that, under the same conditions with t BuOLi, nonstabilized hexafluoroisopropyl 1‐octanesulfonate 3c reacted poorly with benzaldehyde (giving 11 % of 6 ), and trifluoroethyl ester 3d was an optimal olefinating reagent (84 % yield of 6 ).…”

Section: Resultsmentioning

confidence: 93%

Olefination with Sulfonyl Halides and Esters: E‐Selective Synthesis of Alkenes from Semistabilized Carbanion Precursors

et al. 2018

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Carbanions of sulfonyl halides and activated sulfonates add to carbonyl compounds, and so‐formed aldol‐type adducts spontaneously fragment into olefins. This transformation mimics the one‐pot Julia olefination with (hetero)aryl sulfones, but the mechanism of fragmentation involves a four‐membered intermediate, typical for reactivity of phosphorus reagents. Moreover, in contrast to the reactions of sulfones, sulfonates of fluorinated alcohols (TFE and HFI) produce byproducts that are easily removed during workup. In our report, we focus on reactions of unstabilized and semistabilized carbanion precursors: alkylsulfonates, and allyl‐ and benzylsulfonates, respectively. In particular for semistabilized systems, olefins were synthesized as predominant E isomers in good yields. The presented studies reveal that optimal reaction conditions, including the type of base and alcohol groups of the sulfonates, are different depending on stabilization of the carbanion precursors and structure of the carbonyl substrates. The practical synthetic guide is supplemented with a discussion of the mechanism, based on reactivity studies of intermediates and identification of side‐products.

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“…It is known that aprotic polar solvents favor the Michael reaction when charged nucleophiles are employed. 51 The use of THF, a solvent of lower polarity led to poor yield of 10b along with a complex mixture of products (entry 4). On the other hand, the use tetrabutylammonium fluoride trihydrate, as basic catalyst, produced 10b and 10c in similar yields to the previously obtained results (entries 5, 6).…”

Section: Scheme 2 Synthesis Of 15 From 14 Via Domino Reduction-lactammentioning

confidence: 99%

Divergent and Diastereoselective Synthesis of α-Monosubstituted and trans-α,β-Disubstituted γ-Lactams from (S)-N,N-Dibenzyl-α-amino Aldehydes via Henry and Michael Reactions

Meirelis

Vieira²,

Pereira

2020

Synthesis

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γ-Monosubstituted and trans-α,β-disubstituted γ-lactams were diastereoselectively synthesized from common intermediates (S)-N,N-dibenzylated aldehydes derived from natural l-(α)-amino acids, employing a divergent approach. The key features of the routes include diastereoselective Henry and Michael reactions that produced chiral γ-nitroester derivatives, which were subsequently submitted to a tandem reduction-lactamization sequence providing the title compounds. The versatility of routes can allow the preparation of several other mono-, di-, or tri-substituted γ-lactams.

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Benefits of a Dual Chemical and Physical Activation: Direct aza-Michael Addition of Anilines Promoted by Solvent Effect under High Pressure

Abstract: The unique combination of hexafluoroisopropanol (HFIP) employed as solvent and hyperbaric conditions (10-15 kbar) allows unprecedented 1,4-addition of poor nucleophiles, such as aromatic amines, onto sluggish (cumbersome) Michael acceptors without any promoter or workup.

Cited by 38 publications

References 47 publications

Conjugate Addition of 3-Buytn-2-one to Anilines in Ethanol: Alkene Geometric Insights through In Situ FTIR Monitoring

Conjugate Addition of 3-Buytn-2-one to Anilines in Ethanol: Alkene Geometric Insights through In Situ FTIR Monitoring

Olefination with Sulfonyl Halides and Esters: E‐Selective Synthesis of Alkenes from Semistabilized Carbanion Precursors

Divergent and Diastereoselective Synthesis of α-Monosubstituted and trans-α,β-Disubstituted γ-Lactams from (S)-N,N-Dibenzyl-α-amino Aldehydes via Henry and Michael Reactions

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