Diels-Alder reactions of 1-amino-1,3-dienes and related systems

Nájera, Carmén; Sansano, José M.; Yus, Miguel

doi:10.1016/j.tet.2021.132316

Cited by 7 publications

(2 citation statements)

References 344 publications

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“…As a result, investigations describing new applications of this venerable transformation continue to emerge in the literature [1][2][3][4][5][6][7][8]. Not unexpectedly, this reaction has been applied to the synthesis of both simple and complex heterocyclic molecules [9] and, in particular, vinyl heterocycles [10] have proven to be useful in synthesis [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Our lab has explored the chemistry of 4-vinylimidazoles extensively and has reported both inter-and intramolecular variants for the construction of polysubstituted tetrahydro-and dihydrobenzimidazoles; [25][26][27][28][29][30][31][32][33][34] these investigations continue.…”

Section: Introductionmentioning

confidence: 99%

Room Temperature Diels–Alder Reactions of 4-Vinylimidazoles

Fulton,

Hartzell,

Dias

et al. 2024

Molecules

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In the course of studying Diels–Alder reactions of 4-vinylimidazoles with N-phenylmaleimide, it was discovered that they engage in cycloaddition at room temperature to give high yields of the initial cycloadduct as a single stereoisomer. In certain cases, the product precipitated out of the reaction mixture and could be isolated by simple filtration, thereby avoiding issues with aromatization observed during chromatographic purification. Given these results, intramolecular variants using doubly activated dienophiles were also investigated at room temperature. Amides underwent cycloaddition at room temperature in modest yields, but the initial adducts were not isolable with Nimid-benzyl-protected systems. Attempts to extend these results to the corresponding esters and hydroxamate were less successful with these substrates only undergoing cycloaddition at elevated temperatures in lower yields. Density functional theory calculations were performed to evaluate the putative transition states for both the inter- and intramolecular variants to rationalize experimental observations.

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Section: Introductionmentioning

confidence: 99%

Room Temperature Diels–Alder Reactions of 4-Vinylimidazoles

Fulton,

Hartzell,

Dias

et al. 2024

Molecules

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“…The 2‐pyridones and N ‐substituted 2‐pyridone derivatives represent an essential class in heterocyclic chemistry, natural products, and medicinal chemistry (Figure 1) [1]. Several methods have been developed for synthesizing these compounds [1a], including pyridinium salt chemistry [2], Dieckmann‐type condensations [3], Hetero Diels‐Alder reaction [4], so forth. Generally, most of them involve a multistep procedure, selectivity/substrate scope issue, harsh reaction conditions, and poor yield due to the formation of side products.…”

Section: Introductionmentioning

confidence: 99%

Amidate ion‐mediated intramolecular ring transformation of 2‐pyrones to 2‐pyridones

Kumar

Kumari

Kaur

et al. 2023

Journal of Heterocyclic Chem

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Herein, we report a new and cost‐effective methodology for synthesizing N‐substituted 2‐pyridone‐3‐carboxylic acids (2) from 2‐pyrone‐3‐carboxamides (1) with a good yield at room temperature. The notable feature of this reaction is the promotion of amidate ion formation mediated by NaH to initiate intramolecular ring transformation. In addition to ring transformation, simultaneous decarboxylation and substitution under the metal‐free condition in one pot have been achieved to yield N‐substituted 2‐pyridones (3) from 1.

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Chiral Phosphoric Acid‐Catalyzed Enantioselective Formal [4+2] Cycloaddition Between Dienecarbamates and 2‐Benzothioazolimines

Montinho-inacio

Iorga

et al. 2022

Adv Synth Catal

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An enantioselective chiral phosphoric acid catalyzed formal [4+2] cycloaddition between 2‐benzothiazolimines and N‐H‐1,3‐dienecarbamates is described. A divergence in reaction pathways was observed depending on the dienes employed. The reaction performed with 4‐substituted dienes produced benzothiazolopyrimidines as major product in yields ranging from 42 to 67%, as single diastereoisomer and with enantioselectivity between 93 and 99%. The same reaction performed with 3‐substituted dienes, however, gave highly enantioenriched 1,2,3,4‐tetrahydroquinolines as the major products albeit with moderate diastereoselectivity.

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Diels-Alder reactions of 1-amino-1,3-dienes and related systems

Cited by 7 publications

References 344 publications

Room Temperature Diels–Alder Reactions of 4-Vinylimidazoles

Room Temperature Diels–Alder Reactions of 4-Vinylimidazoles

Amidate ion‐mediated intramolecular ring transformation of 2‐pyrones to 2‐pyridones

Chiral Phosphoric Acid‐Catalyzed Enantioselective Formal [4+2] Cycloaddition Between Dienecarbamates and 2‐Benzothioazolimines

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