Desymmetrization of 2‐Cyano‐<i>N</i>‐tosylbenzylidenimine with Thiols and Organocatalytic Heterocyclization by Dynamic Resolution: Mechanism Investigation

Velardo, Amalia; Capaccio, Vito; Caruso, Tonino; Mola, Antonia Di; Massa, António; Tedesco, Consiglia; Caporaso, Lucia; Falivene, Laura; Palombi, Laura

doi:10.1002/ejoc.201901499

Cited by 5 publications

(4 citation statements)

References 61 publications

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“…In parentheses is reported the yield of 3a′ (NMR). c The e.e. values were determined by HPLC analysis; the absolute configuration at the chiral center reported in parentheses was assumed by comparison with a pure sample of 3b d PTC conditions: catalyst VIII (10%)/K 2 CO 3 (1 equiv). e 2a 1.2 equiv. …”

Section: Resultsmentioning

confidence: 99%

“… c The e.e. values were determined by HPLC analysis; the absolute configuration at the chiral center reported in parentheses was assumed by comparison with a pure sample of 3b …”

Section: Resultsmentioning

confidence: 99%

“…3-((4-Methoxyphenyl)thio)-2-tosylisoindolin-1-one (3b): 80% yield, 17 mg; spectral and analytical data as reported 5 3-(( 4 1, 145.5, 142.9, 141.2, 136.3, 136.2, 133.9, 129.7, 129.5, 129.3, 129.2, 125.8, 124.5, 124.2, 123.0, 67.4, 21.9, 15.2; HRMS (MALDI-FT ICR) m/z [M + H] + calcd for C 22 H 20 NO 3 S 3 442.0600, found 442.0616. The enantioselectivity was determined by HPLC (Chiralpak IC column, n-hexane/i-PrOH = 60:40, 1.0 mL/min, t 1 = 17.8 min, t 2 = 27.2 min).…”

Section: ■ Concluding Remarksmentioning

confidence: 99%

“…4 To this regard, we only had mediocre success by developing a two-step procedure as depicted in Scheme 1. As outlined by us in detail in an integrated experimental and theoretical study, 5 the reaction involved the addition of RSH to the imine 1a, a dynamic asymmetric transformation of the intermediate 1A, and a subsequent hydrolysis of the isoindolidin-imine 2A.…”

Section: ■ Introductionmentioning

confidence: 99%

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The First Highly Enantioselective Synthesis of 3-Sulfinyl-Substituted Isoindolinones Having Adjacent Carbon and Sulfur Stereocenters

et al. 2021

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A highly stereoselective access to 3-sulfinyl-substituted isoindolinones has been achieved by a tandem organocatalytic addition/cyclization reaction of 2-carbobenzyloxy-N-tosylbenzylidenimine with thiols and succeeding diastereoselective oxidation with MCPBA. First, enantioenriched isoindolinone N,S-acetals have been obtained through a dynamic kinetic asymmetric transformation induced by a bifunctional chiral thiourea organocatalyst. In turn, the newly created carbon stereocenter enabled a high diastereocontrol in the subsequent sulfoxidation. Based on DFT calculations, a theoretical rationale for the stereoselectivity of the oxidation reaction is also provided.

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Section: Resultsmentioning

confidence: 99%

“… c The e.e. values were determined by HPLC analysis; the absolute configuration at the chiral center reported in parentheses was assumed by comparison with a pure sample of 3b …”

Section: Resultsmentioning

confidence: 99%

Section: ■ Concluding Remarksmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The First Highly Enantioselective Synthesis of 3-Sulfinyl-Substituted Isoindolinones Having Adjacent Carbon and Sulfur Stereocenters

et al. 2021

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Unrevealing the Nitrogen Elusive Chirality of 3‐Sulfanyl and 3‐Sulfinyl N‐Tosyl Isoindolinones by ECD Spectra: An Experimental and Theoretical Investigation

Palombi,

Monti,

Scarel

et al. 2024

Chemistry A European J

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The nitrogen‐hybridization/pyramidalization of two solvated N‐tosylisoindolinone derivatives having chiral residues in adjacent (I) or adjacent and distal (II) position has been investigated by a theoretical‐computational procedure based on Molecular Dynamics simulations and Quantum‐Chemical calculations. After validation of our strategy in providing a reliable repertory of conformations through the modeling of the electronic circular dichroism (EDC) spectra, the electronic features associated with N‐pyramidalization were further characterized by Natural Bond Order (NBO) analysis. Using the N‐geometry found in crystal structures as a reference, our findings reveal that the presence of neighbouring chiral centers generates sharper N‐pyramidalization in solution than in the solid state, both in I and II. Furthermore, although NBO analysis confirms that the N‐lactam mostly retains the sp2 character, its slight configurational distortion (ξI = 13°; ξII = 21°) emerges significantly in the chiroptical activities exhibited by I and II in ECD spectra, thereby substantiating these N‐lactams as configurationally stable chiral centers.

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Organocatalytic Dynamic Kinetic Resolution: An Update

Pellissier

2022

Eur J Org Chem

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It is only in the two last decades that the first examples of organocatalytic dynamic kinetic resolutions (DKRs) have been disclosed. These methodologies allow resolving racemic compounds with up to quantitative yield. Today, a variety of chiral organocatalysts are capable of providing excellent enantioselectivities in many types of transformations evolving through DKR. The goal of this review is to update the field of organo-catalytic DKRs since 2016. It is divided into six sections, according to the different types of organocatalysts employed in these reactions, such as Brønsted acid catalysts, hydrogenbonding catalysts, N-heterocyclic carbene catalysts, Lewis base catalysts, phase-transfer catalysts, and cinchona alkaloid-based Brønsted base catalysts.

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Desymmetrization of 2‐Cyano‐N‐tosylbenzylidenimine with Thiols and Organocatalytic Heterocyclization by Dynamic Resolution: Mechanism Investigation

Cited by 5 publications

References 61 publications

The First Highly Enantioselective Synthesis of 3-Sulfinyl-Substituted Isoindolinones Having Adjacent Carbon and Sulfur Stereocenters

The First Highly Enantioselective Synthesis of 3-Sulfinyl-Substituted Isoindolinones Having Adjacent Carbon and Sulfur Stereocenters

Unrevealing the Nitrogen Elusive Chirality of 3‐Sulfanyl and 3‐Sulfinyl N‐Tosyl Isoindolinones by ECD Spectra: An Experimental and Theoretical Investigation

Organocatalytic Dynamic Kinetic Resolution: An Update

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