Organocatalytic asymmetric decarboxylative cyanomethylation of isatins using l-proline derived bifunctional thiourea

Gajulapalli, V. Pratap Reddy; Vinayagam, Poopathy; Kesavan, Venkitasamy

doi:10.1039/c4ob00271g

Cited by 31 publications

(7 citation statements)

References 33 publications

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“…Thiourea derivatives constitute a privileged class of organocatalysts due to the possibility of establishing multiple hydrogen-bond interactions with substrates, when used in asymmetric catalysis [22,23]. Although several thioureas derived from proline have been synthesized and used as organocatalysts in various asymmetric reactions with high stereoselectivities, [24][25][26][27][28][29][30] thioureas derived from thiazolidines are scarce in the literature. Schneider and coworkers reported, in 2015, the synthesis of thioureas containing a thiazolidine moiety.…”

Section: Scheme 1 Synthesis Of Organocatalysts 3a-6amentioning

confidence: 99%

Chiral Thiazolidine based Organocatalysts: Synthesis and Application in Asymmetric Aldol Reactions

Félix

Simões

Sousa

et al. 2020

LOC

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Several novel chiral organocatalysts derived from thiazolidines containing amide and thioureia functionalities were synthesized in good yields. These organocatalysts were tested in the asymmetric aldol reaction of acetone with p-nitrobenzaldehyde. Reaction parameters such as reaction time, catalyst loading and solvent were optimized. Products with conversions up to 84% and enantiomeric ratios (er) up to 84.5:15.5 (R:S) were obtained. The effect of several chiral and non-chiral additives on the reactivity and selectivity of the reaction was also evaluated. The reaction was extended to other aromatic aldehydes with the best organocatalyst and when p-bromobenzaldehyde was used, an er of 94.5:5.5 (R:S) was obtained.

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Section: Scheme 1 Synthesis Of Organocatalysts 3a-6amentioning

confidence: 99%

Chiral Thiazolidine based Organocatalysts: Synthesis and Application in Asymmetric Aldol Reactions

Félix

Simões

Sousa

et al. 2020

LOC

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“…More recently, Kesavan and co-workers reported an asymmetric decarboxylative cyanomethylation of isatins with cyanoacetic acid using the L-proline-derived thiourea as the catalyst (cat. 30 ), giving the cyanomethylated products in good yields (up to 82%) and with excellent enantioselectivities (up to 90% ee, Scheme 44 ) [ 61 ]. The reactions were performed in methyl tert -butyl ether at room temperature with 5 mol % of catalyst loading.…”

Section: Reviewmentioning

confidence: 99%

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

Yu¹,

Xing²,

Yu³

et al. 2016

Beilstein J. Org. Chem.

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SummaryOxindole scaffolds are prevalent in natural products and have been recognized as privileged substructures in new drug discovery. Several oxindole-containing compounds have advanced into clinical trials for the treatment of different diseases. Among these compounds, enantioenriched 3-hydroxyoxindole scaffolds also exist in natural products and have proven to possess promising biological activities. A large number of catalytic asymmetric strategies toward the construction of 3-hydroxyoxindoles based on transition metal catalysis and organocatalysis have been reported in the last decades. Additionally, 3-hydroxyoxindoles as versatile precursors have also been used in the total synthesis of natural products and for constructing structurally novel scaffolds. In this review, we aim to provide an overview about the catalytic asymmetric synthesis of biologically important 3-substituted 3-hydroxyoxindoles and 3-hydroxyoxindole-based further transformations.

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“…However, in the above two catalytic asymmetric decarboxylative reactions, cyanoacetic acid was only employed as the precursor for decarboxylative nucleophile generation 6,7 by anion exchange with CuOAc–bisphosphine complex (decarboxylative protonation was a side reaction 8 ). However, the acidic nature of cyanoacetic acid was not fully utilized.…”

Section: Introductionmentioning

confidence: 99%

Copper(I)-catalyzed asymmetric decarboxylative Mannich reaction enabled by acidic activation of 2H-azirines

2019

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Chiral aziridines are structure units found in many biologically active compounds and are important building blocks in organic synthesis. Herein, by merging nucleophilic generation through copper(I)-catalyzed decarboxylation and activation of poorly electrophilic 2 H -azirines through protonation with carboxylic acids, an asymmetric decarboxylative Mannich reaction between α,α-disubstituted cyanoacetic acids and 2 H -azirines is uncovered, which leads to generation of chiral aziridines containing vicinal tetrasubstituted and acyclic quaternary stereogenic carbon centers in good to excellent diastereo- and enantioselectivities. At last, transformations of the produced chiral aziridine are successfully carried out to deliver synthetically useful compounds.

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Organocatalytic asymmetric decarboxylative cyanomethylation of isatins using l-proline derived bifunctional thiourea

Cited by 31 publications

References 33 publications

Chiral Thiazolidine based Organocatalysts: Synthesis and Application in Asymmetric Aldol Reactions

Chiral Thiazolidine based Organocatalysts: Synthesis and Application in Asymmetric Aldol Reactions

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

Copper(I)-catalyzed asymmetric decarboxylative Mannich reaction enabled by acidic activation of 2H-azirines

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