Asymmetric organocatalytic direct Mannich reaction of acetylacetone and isatin derived ketimines: Low catalyst loading in chiral cinchona-squaramides

İşibol, Duygu; Karahan, Seda; Tanyeli, Cihangir

doi:10.1016/j.tetlet.2017.12.081

Cited by 17 publications

(6 citation statements)

References 68 publications

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“…In 2016, a series of 1,3‐diamine‐derived bifunctional squaramide catalysts from camphor were prepared and tested in the Mannich reaction of 1,3‐dicarbonyl compounds to isatin‐derived ketimines, [26] but only 69% ee was observed. A similar study that isatin‐derived ketimines 1 with 1,3‐dicarbonyl compounds 2 catalyzed by C2 was developed by Tanyeli group [27] in 2018 (Scheme 2). The authors attempted to explore the effect of sterically hindered hydrocarbons with different structures in the squaramide catalysts and they chose 1‐adamantyl, 2‐adamantyl and t ‐butyl substituted squaramide catalysts, they all showed pretty good results, especially the 2‐adamantyl‐derived squaramide catalyst had the best effect.…”

Section: Asymmetric Mannich Reactions Using Isatin‐derived Ketiminesmentioning

confidence: 91%

Recent Advances in Squaramide‐Catalyzed Asymmetric Mannich Reactions

Hou

2020

Adv Synth Catal

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Bifunctional squaramides as a branch of organo-catalysts showed powerful strategies in the art of asymmetric synthesis, and they have been proved to be highly efficient and versatile catalysts for constructing complex molecular structures and chiral biologically active compounds. In this review, we summarized recent advances in bifunctional squaramide-catalyzed asymmetric Mannich reactions. 1. Introduction 2. Asymmetric Mannich Reactions using Isatin-Derived Ketimines 3. Asymmetric Mannich Reactions using N-2,2,2trifluoroethyl Isatin-Derived Ketimines 4. Asymmetric Mannich Reactions using Pyrazolone-Derived Ketimines 5. Asymmetric Mannich Reactions using the Cyclic Imines and the Straight-Chain Imines 6. Asymmetric Mannich Reactions using other Substrates 7. Summary and Outlook

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Section: Asymmetric Mannich Reactions Using Isatin‐derived Ketiminesmentioning

confidence: 91%

Recent Advances in Squaramide‐Catalyzed Asymmetric Mannich Reactions

Hou

2020

Adv Synth Catal

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“…A highly asymmetric synthesis of 3‐amino‐2‐oxindoles via Mannich reaction of acetylacetone and N ‐carbamoyl isatin ketimine has been reported in 2018 by Tanyeli and co‐workers. The relevant chiral adducts were synthesized using very low (about 1 mol %) catalyst loading of 2‐adamantyl functionalized bifunctional cinchona‐squaramide in high yields (up to 98 %) and ee s (up to>99 %) [63] . Under the optimal conditions, the generality of this reaction was examined using various isatin ketimines having different groups at amide nitrogen and electron donating/withdrawing substituents on aryl moiety.…”

Section: Organocatalyzed Asymmetric Mannich Reactionmentioning

confidence: 99%

“…In this reaction, different N ‐carbamoyl protecting groups were reacted with acetylacetone using organocatalyst (Scheme 21). [63] …”

Section: Organocatalyzed Asymmetric Mannich Reactionmentioning

confidence: 99%

Organocatalyzed Asymmetric Mannich Reaction: An Update

et al. 2021

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The Mannich reaction is a multicomponent reaction resulting in aminoalkylation of an acidic proton placed next to a carbonyl functional group. It involves an appropriate carbonyl compound, such as formaldehyde and a primary or secondary amine or ammonia. The final product is a β‐amino‐carbonyl compound known as a Mannich base. Reactions between aldimines and α‐methylene carbonyls are also considered as Mannich reaction since these imines are generated from the reaction of amines and aldehydes. It comprises the reaction of primary or secondary amines or ammonia, formaldehyde and appropriate α‐CH‐acidic compounds (nucleophiles) such as carbonyl compounds having α‐CH‐acidic, nitriles, acetylenes, aliphatic nitro compounds, α‐alkyl‐pyridines or imines. Owing to the development of asymmetric organocatalysis, reports on asymmetric Mannich reaction have been drastically increased. The asymmetric Mannich reaction offers access to enantioenriched β‐amino ketones or β‐amino aldehydes, which are present as a scaffold in several natural products. Organocatalysts have been developed not only as a supplement to metal‐catalyzed reactions or to biocatalysis, but nowadays, they are extensively used for the synthesis of various optically pure compounds that could not be achieved via metal‐ or biocatalyzed reactions. In this review, we try to update the advances in organocatalyzed asymmetric Mannich reactions, covering the recent advances of the subject from 2008 to date.

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“…In 2018, Tanyeli et al reinvestigated this type of reactions in the presence of related cinchona alkaloid-derived squaramide catalyst 8 [37]. Indeed, the reaction of acetylacetone ( 5a ) with various N -alkoxycarbonylisatin imines 3 and 9 in the presence of only 1 mol % of catalyst 8 in diethyl ether as solvent afforded at room temperature the corresponding chiral Mannich products 7 and 10 in low to nearly quantitative yields (29–98%) combined with moderate to excellent enantioselectivities (41 to >99% ee) as shown in Scheme 3.…”

Section: Reviewmentioning

confidence: 99%