Asymmetric synthesis XXII: Asymmetric catalytic trimethylsilylcyanation of benzaldehyde by novel Ti(IV)-chiral schiff base complexes

Jiang, Yaozhong; Zhou, Xiangge; Hu, Wenhao; Lanjun, Wu; Mi, Aiqiao

doi:10.1016/0957-4166(95)00025-k

Cited by 59 publications

(3 citation statements)

References 10 publications

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“…Also, the ligand/titanium stoichiometry had a marked effect on the enantioselectivity. In contrast to the system of Oguni and co‐workers, the reactions catalyzed by stoichiometric quantities of catalyst were found to give better ee values than those run with substoichiometric loading 43…”

Section: Catalysts For the Cyanation Of Aldehydescontrasting

confidence: 81%

Chemically Catalyzed Asymmetric Cyanohydrin Syntheses

Brunel¹,

2004

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Over the past two decades, significant advances have been made towards developing chemically catalyzed asymmetric cyanohydrin syntheses. Preparations that were classically highly substrate specific, often using stoichiometric quantities of reagents, have been revolutionized by a new generation of catalysts. Methods currently available rival, and in many cases surpass, enzymatic procedures in terms of synthetic utility, generic applicability, and enantioselectivity. Such protocols are increasingly finding application in the syntheses of both biologically active natural products and therapeutically important synthetic compounds.

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Section: Catalysts For the Cyanation Of Aldehydescontrasting

confidence: 81%

Chemically Catalyzed Asymmetric Cyanohydrin Syntheses

Brunel¹,

2004

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“…interest particularly during the last two decades [1][2][3][11][12][13]. A number of methods for the preparation of optically pure cyanohydrins have been developed using various chiral catalysts [14,15], such as cyclic dipeptides [16,17], as well as chiral complexes with titanium [18,19]. Aluminum [20] and boron [21].…”

Section: Introductionmentioning

confidence: 99%

Preparation and reactions of optically active cyanohydrins using the (R)-hydroxynitrile lyase from Prunus amygdalus

Yosef

Morsy

Mahran

et al. 2007

JICS

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Cyanuration of 2-naphthaldehyde (1) and 5-methyl-2-furaldehyde (2) yielded the racemic 2-hydroxy-2-(β-naphthyl)ethanenitrile (R,S)-3 and 2-hydroxy-2-(5-methyl-2-furyl)ethanenitrile (R,S)-5, respectively. The same reaction can be completed by using acetone cyanohydrin (4) as a transcyanating agent. The optically active (R)-3 and (S)-5 could be respectively obtained by hydrocyanation of 1 and 2 using (R)-hydroxynitrile lyase (R)-PaHNL [EC 4.1.2.10] from almonds (Prunus amygdalus) as a chiral catalyst. Cyanohydrins 3 and 5 in their racemic and optically active forms undergo a number of transformations which involve either the hydroxyl group or the cyanide function. Moreover, derivatization of 3 and 5 with (S)-Naproxen ® chloride (S)-14 gave the respective diastereoisomers. The optical activity of (R)-3 and (S)-5 as well as their derivatives were recorded. The postulated structures for the new products were supported with compatible elementary and spectroscopic (IR, 1 H NMR, 13 C NMR, MS, and single crystal X-Ray crystallography) analyses. The antimicrobial activity of some selected racemic new products and their respective optically active analogues were also undertaken.

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“…Auch das stöchiometrische Verhältnis Ligand/Titan hatte einen deutlichen Einfluss auf den Enantiomerenüberschuss. Im Unterschied zum Oguni‐System verliefen Reaktionen mit stöchiometrischen Anteilen des Titankomplexes mit höheren Enantiomerenüberschüssen als solche mit substöchiometrischen Anteilen 43…”

Section: Katalysatoren Für Die Cyanierung Von Aldehydenunclassified

Chemisch katalysierte asymmetrische Cyanhydrinsynthesen

Brunel

Holmes

2004

Angewandte Chemie

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In den letzten 20 Jahren wurden bemerkenswerte Fortschritte bei der Entwicklung chemisch katalysierter asymmetrischer Cyanhydrinsynthesen erzielt. Klassische, meist stöchiometrische Syntheseverfahren mit hoher Substratspezifität sind durch eine neue Generation von Katalysatoren revolutioniert worden. Die heute verfügbaren Methoden konkurrieren mit enzymatischen Verfahren und übertreffen diese in vielen Fällen hinsichtlich Anwendungsbreite und Enantioselektivität. Insbesondere in der Synthese von biologisch wichtigen Naturstoffen und therapeutisch relevanten synthetischen Verbindungen finden chemisch katalysierte asymmetrische Cyanhydrinsynthesen vermehrt Anwendung.

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Asymmetric synthesis XXII: Asymmetric catalytic trimethylsilylcyanation of benzaldehyde by novel Ti(IV)-chiral schiff base complexes

Cited by 59 publications

References 10 publications

Chemically Catalyzed Asymmetric Cyanohydrin Syntheses

Chemically Catalyzed Asymmetric Cyanohydrin Syntheses

Preparation and reactions of optically active cyanohydrins using the (R)-hydroxynitrile lyase from Prunus amygdalus

Chemisch katalysierte asymmetrische Cyanhydrinsynthesen

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