Synthesis of a new <i>C</i><sub>2</sub>‐symmetric chiral catalyst and its application in the catalytic asymmetric borane reduction of prochiral ketones

Zhou, Yan; Wang, Wenhua; Dou, Wei; Tang, Xiaoliang; Liu, Weisheng

doi:10.1002/chir.20503

Cited by 13 publications

(4 citation statements)

References 33 publications

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“…On the other hand, 1,2,4- and 1,3,4-oxadiazoles have also been extensively studied in the past decade [ 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. A wide range of biologically active pharmacophores possess these five-membered heteroaromatic ring systems with remarkable biological properties including sphinosine kinase inhibitor [ 29 ], diacylglycerol acyltransferase 1 (DGAT-1) inhibitor [ 30 ], glycogen synthase kinase (GSK-3) inhibitor [ 31 ], sirtuin (SIRT) inhibitor [ 32 ] and methionine aminopeptidase inhibitor activities [ 33 ].…”

Section: Introductionmentioning

confidence: 99%

Stereoselective Synthesis, Synthetic and Pharmacological Application of Monoterpene-Based 1,2,4- and 1,3,4-Oxadiazoles

Gonda

Bérdi

Zupkó

et al. 2017

IJMS

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Stereoselective synthesis of monoterpene-based 1,2,4- and 1,3,4-oxadiazole derivatives was accomplished starting from α,β-unsaturated carboxylic acids, obtained by the oxidation of (−)-2-carene-3-aldehyde and commercially available (−)-myrtenal. 1,2,4-Oxadiazoles were prepared in two steps via the corresponding O-acylamidoxime intermediates, which then underwent cyclisation induced by tetrabutylammonium fluoride (TBAF) under mild reaction conditions. Stereoselective dihydroxylation in highly stereospecific reactions with the OsO4/NMO (N-methylmorpholine N-oxide) system produced α,β-dihydroxy 1,2,4-oxadiazoles. Pinane-based 1,3,4-oxadiazoles were obtained similarly from acids by coupling with acyl hydrazines followed by POCl3-mediated dehydrative ring closure. In the case of the arane counterpart, the rearrangement of the constrained carane system occurred with the loss of chirality under the same conditions. Stereoselective dihydroxylation with OsO4/NMO produced α,β-dihydroxy 1,3,4-oxadiazoles. The prepared diols were applied as chiral catalysts in the enantioselective addition of diethylzinc to aldehydes. All compounds were screened in vitro for their antiproliferative effects against four malignant human adherent cell lines by means of the MTT assay with the O-acylated amidoxime intermediates exerting remarkable antiproliferative action.

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Section: Introductionmentioning

confidence: 99%

Stereoselective Synthesis, Synthetic and Pharmacological Application of Monoterpene-Based 1,2,4- and 1,3,4-Oxadiazoles

Gonda

Bérdi

Zupkó

et al. 2017

IJMS

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“…40,42 The use of the phenyl analogue Ic seems to have advantages in the reduction of 1-(4-nitrophenyl)ethanone 1i, 12 while the derivatives Id-e are good catalysts for the preparation of the trifluoroalcohol 8c. Of all the bi-and tridentate catalysts prepared and tested, [16][17][18][19][20][21] catalyst IV appears to be the most efficient. Catalyst IV 16 performs especially well in the reduction of 2,2,2-trifluoro-1-phenylethanone 4c and 1-(3,5-dinitrophenyl)ethanone (95% ee, data not shown).…”

Section: Comparison Of Catalyst II With Other Prolinol Systemsmentioning

confidence: 99%

“…[13][14][15] Also, some C2 and C3 symmetric diphenylprolinol based systems have been evaluated in asymmetric borane reductions. [16][17][18][19][20][21] 0957-4166/$ -see front matter Ó 2011 Elsevier Ltd. All rights reserved. …”

Section: Introductionmentioning

confidence: 99%

Enantioselectivity, swelling and stability of 4-hydroxyprolinol containing acrylic polymer beads in the asymmetric reduction of ketones

Thvedt¹,

Kristensen²,

Sundby³

et al. 2011

Tetrahedron: Asymmetry

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a b s t r a c tA new 4-hydroxy-a,a-diphenyl-L-prolinol containing polymethacrylate, prepared without chromatography by a large scale adaptable synthesis, has been evaluated as a catalyst in the asymmetric reduction of 1-arylethanones. Using 1-(4-bromophenyl)ethanone as the model substance, the reduction was tested with various borane sources and solvents. The best swellings of the polymer and reactivity were observed in THF using N,N-diethylaniline borane complex as the hydride source. The selectivity in the reduction of 1-(4-bromophenyl)ethanone was found to depend on the substrate concentration and catalyst loading. Using the best conditions identified, a series of 1-arylethanones was reduced to their corresponding enantioenriched secondary alcohols. High rates and ee-values were obtained in the reduction of acetophenones containing electron withdrawing groups in the aromatic ring, whereas a moderate selectivity was the result for products containing electron donating aromatic substituents. Upon recovery of the polymer beads, it was found that vacuum drying led to extensive rupturing, while the bead structure was intact if washed with methanol and air dried at atmospheric pressure. Repeated use of the polymer catalyst gave the product alcohol with a lower 90% ee. Elemental analysis showed this to be due to the loss of the chiral prolinol unit.

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“…Os métodos experimentais até a obtenção do composto (5) foram baseados na literatura. 107 assim como os de obtenção dos compostos (9), (10), (11) e (12). 42 Os ligantes finais terão a sua caracterização totalmente discutida na seção Resultados e Disscussão.…”

Section: Síntesesunclassified

Desenvolvimento de catalisadores e sistemas enzimáticos para a redução do CO2

Netto¹,

Cunha²

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O gás carbônico é a fonte primária de carbono ideal para se obter novos compostos, devido principalmente à sua abundância, atoxidade e ao fato de ser renovável. Desta forma, novos métodos de introduzir o CO 2 em rotas sintéticas se fazem necessários. Dentre os possíveis métodos, nesta tese foram estudadas duas rotas diferentes de utilização do gás carbônico: uma, empregando complexos bimetálicos como catalisadores da inserção do CO 2 em alcenos e alcanos e outra utilizando enzimas imobilizadas em partículas magnéticas, atuantes no ciclo de redução do CO 2 ao metanol.Os complexos bimetálicos foram construídos a partir do ligante de ponte, bispirrolidyl-fenil (BPP) incorporando grupos difenilmetanol e difenilfosfino em suas arquiteturas moleculares. Sua inspiração partiu de sistemas biomiméticos para a redução do CO 2 , e foi direcionada para a carboxilação de hidrocarbonetos. Nas reações de acoplamento carbono-carbono, observou-se que com o iodeto de metila, os complexos foram capazes de transformar o gás carbônico e produzir acetato de metila. Já nas reações com 1-deceno, isobutano e iso-octano, apenas três complexos se mostraram eficientes: BPP(ONi,ONi), BPP(OZn,OPPh 2 Pd) e BPP(OPPh 2 Pd,OPPh 2 Pd).Na rota enzimática, fez-se uso de enzimas imobilizadas do tipo desidrogenase e três tipos de nanopartículas magnéticas (MagNP) como suporte (MagNP-APTS, MagNP@SiO 2 -APTS e MagNP-APTS/Glioxil-Agarose, APTS = aminopropiltrimetoxissilano). Observou-se que para a imobilização da álcool desidrogenase e da formaldeído desidrogenase, o melhor suporte foi a MagNP@SiO 2 -APTS, enquanto para a formato desidrogenase, o melhor suporte de imobilização foi a MagNP-APTS. Para a glutamato desidrogenase, um sistema com imobilização via múltiplos pontos, como na MagNP-APTS/Glioxil-Agarose, conduziu a um melhor desempenho, . Os melhores sistemas enzima-suporte foram utilizados em uma reação multi-enzimática com CO 2 , NADH e glutamato para a obtenção de formaldeído e metanol.Os dois métodos de redução do gás carbônico se mostraram capazes de realizar o objetivo da tese, que é a transformação do CO 2 em produtos de maior valor agregado. CO 2 is a primary world carbon source readily available for the production of new compounds, under sustainable conditions due to its great abundance and non-toxic, renewable characteristics. Hence, there is a compulsive interest to develop new methodologies capable of introducing carbon dioxide in the chemical synthetic routes. Among the many possible alternatives, two different strategies were pursued this thesis: one using bimetallic complexes as catalysts, and the other one using enzymes supported on superparamagnetic nanoparticles. PalavrasThe bimetallic complexes were based on the bridging bis-pyrrolidyl-phenol (BPP) architecture encompassing diphenylmethanol and diphenylphosphino groups. They were inspired in biomimetic systems for the chemical reduction of CO 2 and employed in the carboxylation of hydrocarbons. In such carbon-carbon coupling reactions, the bimetallic complexes were able to catal...

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Synthesis of a new C₂‐symmetric chiral catalyst and its application in the catalytic asymmetric borane reduction of prochiral ketones

Cited by 13 publications

References 33 publications

Stereoselective Synthesis, Synthetic and Pharmacological Application of Monoterpene-Based 1,2,4- and 1,3,4-Oxadiazoles

Stereoselective Synthesis, Synthetic and Pharmacological Application of Monoterpene-Based 1,2,4- and 1,3,4-Oxadiazoles

Enantioselectivity, swelling and stability of 4-hydroxyprolinol containing acrylic polymer beads in the asymmetric reduction of ketones

Desenvolvimento de catalisadores e sistemas enzimáticos para a redução do CO2

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Synthesis of a new C2‐symmetric chiral catalyst and its application in the catalytic asymmetric borane reduction of prochiral ketones

Cited by 13 publications

References 33 publications

Stereoselective Synthesis, Synthetic and Pharmacological Application of Monoterpene-Based 1,2,4- and 1,3,4-Oxadiazoles

Stereoselective Synthesis, Synthetic and Pharmacological Application of Monoterpene-Based 1,2,4- and 1,3,4-Oxadiazoles

Enantioselectivity, swelling and stability of 4-hydroxyprolinol containing acrylic polymer beads in the asymmetric reduction of ketones

Desenvolvimento de catalisadores e sistemas enzimáticos para a redução do CO2

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Synthesis of a new C₂‐symmetric chiral catalyst and its application in the catalytic asymmetric borane reduction of prochiral ketones