Water enables transimination between hindered ketimines and β-aminoalcohols and selective protection of a vicinal diamine backbone

Bafqiren, Hanane; Eddine, Jamal Jamal

doi:10.1016/j.tet.2010.06.013

Cited by 5 publications

(4 citation statements)

References 24 publications

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“…We next explored the origin of the nitrogen atom in the indole by employing 15 15 Nf or 14 No ccurs via intermediates C, D,and E (Scheme 5). [28] Forthis to be true,transimination would need to be faster than S N Ar. We hypothesized that the use of electron-withdrawing groups on the toluene would increase the rate of S N Ar and increase the level of incorporation of labeled nitrogen.…”

Section: Zuschriftenmentioning

confidence: 99%

Synthesis of Indoles through Domino Reactions of 2‐Fluorotoluenes and Nitriles

Mao

Wang

et al. 2019

Angew Chem Int Ed

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Indoles are essential heterocycles in medicinal chemistry,a nd therefore,n ovel and efficient approaches to their synthesis are in high demand. Among indoles,2 -aryl indoles have been described as privileged scaffolds.Advanced herein is astraightforward, practical, and transition-metal-free assembly of 2-aryl indoles.Simply combining readily available 2-fluorotoluenes,n itriles,L iN(SiMe 3 ) 2 ,a nd CsF enables the generation of adiverse arrayofindoles (38 examples,48-92 % yield). Ar ange of substituents can be introduced into each position of the indole backbone (C4 to C7, and aryl groups at C2), providing handles for further elaboration. Scheme 1. Transition-metal-free synthesis of indoles.

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Section: Zuschriftenmentioning

confidence: 99%

Synthesis of Indoles through Domino Reactions of 2‐Fluorotoluenes and Nitriles

Mao

Wang

et al. 2019

Angew Chem Int Ed

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“…The choice of ketimine 2a as substrate of the alkylation reaction underlies two main earlier established empirical guidelines; 1) contributions from this laboratory on hindered ketimines revealed that introduction of 1‐naphthyl group as an imine substituent generates steric environment that facilitates separation of geometric, or even atropisomeric, Schiff base stereoisomers; 2) the steric hindrance brought by the 1‐naphthyl group enhances considerably resistance of the imine functional group towards hydrolysis, which in turn contributes to limit racemization of alkylation reaction products.…”

Section: Resultsmentioning

confidence: 99%

A Simple Chiral Cu(II) Complex as an Effective Phase‐Transfer Catalyst for the Enantioselective Alkylation of Dissymmetric Glycinate Ketimines

Bafqiren

Zouihri²,

Gmouh³

et al. 2015

Chirality

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Catalytic asymmetric benzylation of a dissymmetric tert-butylglycinate ketimine, incorporating 1-naphthyl and phenyl groups as the Schiff base substituents, under phase-transfer conditions was investigated. It was interesting to note that the sense of asymmetric induction of the alkylation of Z-imine stereoisomer is opposite to that of the corresponding E stereoisomer with a similar degree of enantioselectivity. More interestingly, the chiral Cu(II) complex of the Schiff base derived from (R)-2-phenylglycinol and 2-hydroxy-1-naphthaldehyde was found to catalyze the same reaction under solid-liquid conditions with comparable enantioselectivity (up to 60% ee) with respect to known cinchona alkaloid catalysts. The solvent/base-system parameter was shown to control the optimal catalytic activity.

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“…22 Recently, Bafquiren and Eddine have studied hindered Schiff base derivatives of trans-1,2-diaminocyclohexane. 23 The differences in chemical shifts found for imino carbons have indicated the presence of anti-and syn-geometric configurations. The intense NOESY effects between protons of naphthyl and alkyl units have proved the anti-configuration of the major stereoisomer.…”

Section: Product Identification and Conformation Studiesmentioning

confidence: 99%

“…33,54,55 The highest values were found for lithium salts in D 2 O. 55 The NMR measurements for the Schiff bases being derivatives of (R)-1-(9-anthryl)-ethylamine and 2-(2 0 -pyridyl or quinolyl)acetophenone [23] have revealed the presence of the rigid conformation of the enamine form. 56…”

Section: H and 13 C Nmr Spectroscopymentioning

confidence: 99%

NMR Studies of Optically Active Schiff Bases

Rozwadowski

2011

Annual Reports on NMR Spectroscopy

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Water enables transimination between hindered ketimines and β-aminoalcohols and selective protection of a vicinal diamine backbone

Cited by 5 publications

References 24 publications

Synthesis of Indoles through Domino Reactions of 2‐Fluorotoluenes and Nitriles

Synthesis of Indoles through Domino Reactions of 2‐Fluorotoluenes and Nitriles

A Simple Chiral Cu(II) Complex as an Effective Phase‐Transfer Catalyst for the Enantioselective Alkylation of Dissymmetric Glycinate Ketimines

NMR Studies of Optically Active Schiff Bases

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