The influence of microwave irradiation on lipase-catalyzed kinetic resolution of racemic secondary alcohols

Bachu, Prabhakar; Gibson, Jennifer S.; Sperry, Jonathan; Brimble, Margaret A.

doi:10.1016/j.tetasy.2007.06.035

Cited by 37 publications

(26 citation statements)

References 43 publications

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“…However, the E-values are low and considered unacceptable for practical purposes, especially in enzymatic resolution. 3 These data are in agreement with those presented by Bachu et al 12 These authors reported that the use of vinyl acetate and iso-propenyl acetate is not always advantageous in biocatalysis because they can form undesirable side products, such as acetaldehyde or acetone which are toxic to the enzyme and can denature the biocatalyst.…”

Section: Screening Of Lipasessupporting

confidence: 90%

“…Reactions performed under MW irradiation proceed faster, are cleaner, present much better yields and are more reproducible than those performed under conventional conditions. [12][13][14][15][16][17] Besides, in some enzymatic reactions the selectivity, such as stereoselectivity or regioselectivity, are clearly influenced. [17][18][19] Yu et al 18 observed that MW irradiation increased both the activity and enantioselectivity of novozym 435, and also the thermal stability and reusability in the resolution of (RS)-2-octanol with vinyl acetate as the acyl donor.…”

Section: Introductionmentioning

confidence: 99%

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The influence of conventional heating and microwave irradiation on the resolution of (RS)-sec-butylamine catalyzed by free or immobilized lipases

Pilissão¹,

Carvalho²,

Nascimento³

2012

J. Braz. Chem. Soc.

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As lipases CAL-B, LPS, LPS-C, LPS-D e a de A. níger, livres ou imobilizadas em filmes de amido de cará (Discorea alata L.), inhame (Colocasia esculenta (L.) Schott) ou de gelatina, foram utilizadas na acilação da (RS)-sec-butilamina com diferentes doadores acila em vários solventes orgânicos sob aquecimento convencional (CH) ou irradiação por microondas (MW). Ao utilizar a lipase de A. niger livre, a conversão foi três vezes maior sob irradiação por MW em relação ao CH a 35 ºC. Usando a lipase de A. niger livre, a (R)-amida foi obtida com 21% de conversão, resultando em valores de ee p > 99% e de E (enantiosseletividade) > 200, em 1 min de reação em MW. Ao utilizar a lipase de A. niger imobilizada em filmes de amido de cará e inhame, em 3 ou 5 min de reação em MW, a amida foi obtida com conversões moderadas, sendo de 8 a 25%, porém com maior seletividade (ee p > 99% e E > 200) em comparação à forma livre (45% de conversão, ee p 81% e 18 para o valor de E).The lipases CAL-B, PSL, PSL-C, PSL-D, and A. niger lipase, free or immobilized in starch (obtained from two types of yam, known in Brazil as "cará" (Discorea alata L.) and "inhame" (Colocasia esculenta (L.) Schott) or gelatin films, were used in the acylation of (RS)-sec-butylamine with different acyl donors in various organic solvents applying conventional heating (CH) or microwave (MW) irradiation. In the case of free A. niger lipase, the conversion degrees were three times higher using MW irradiation when compared to conventional heating at 35 °C. Using free A. niger lipase, the (R)-amide was obtained with a conversion degree of 21%, resulting in ee p > 99% and E-value (enantioselectivity value) > 200, in 1 min of reaction under MW irradiation. When the A. niger lipase was immobilized in yam starch films, the (R)-amide was obtained in moderate conversions of 8-25% after 3 or 5 min of reaction under MW irradiation, but with higher selectivity (ee p > 99% and E > 200) in comparison with the free form (conversion degree of 45%, ee p 81% and E value of 18).

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Section: Screening Of Lipasessupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

The influence of conventional heating and microwave irradiation on the resolution of (RS)-sec-butylamine catalyzed by free or immobilized lipases

Pilissão¹,

Carvalho²,

Nascimento³

2012

J. Braz. Chem. Soc.

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“…Previous studies of lipase-catalyzed kinetic resolutions of secondary alcohols under microwave irradiation have in several cases shown enhancements in both rate and/or enantioselectivity. 10 For immobilized lipases, the reactivities and enantioselectivities in microwave and oil bath experiments were identical to the kinetic resolution of 1-(±)-phenylethanol. 11 CALB catalyzed the resolution of (R,S)-2-octanol with vinyl acetate as the acyl donor under microwave irradiation and conventional heating.…”

Section: Introductionmentioning

confidence: 74%

“…The toluene has higher boiling point, it appear to be an excellent solvent for the investigation of microwave-assisted kinetic resolution. 10 The kinetic resolution of (±)-mandelonitrile (1) yielded the (S)-mandelonitrile (2) with good conversion and optical purity (c 38-40% and 92-93% ee, entries 17-19, Table 1) under microwave irradiation. The kinetic resolution under conventional system occurred with a longer time (c 46-48%, > 98% ee, 168-184 h, entries 10 and 11, Table 1).…”

Section: Resultsmentioning

confidence: 97%

Lipase-catalyzed kinetic resolution of (±)-mandelonitrile under conventional condition and microwave irradiation

Ribeiro¹,

Oliveira²,

Porto³

2012

J. Braz. Chem. Soc.

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A resolução cinética da (±)-mandelonitrila foi realizada utilizando a lipase de Candida antarctica sob condição convencional (agitação orbital) e irradiação de micro-ondas em tolueno, produzindo o acetato de (S)-mandelonitrila com elevada seletividade (92-98% ee, excesso enantiomérico). O álcool remanescente da (R)-mandelonitrila sob irradiação de micro-ondas e agitação orbital foi parcialmente convertido em benzaldeído via equilíbrio químico espontâneo. O acetato de (S)-mandelonitrila foi produzido com 92% ee e rendimento de 35% em 8 h de reação sobre irradiação de micro-ondas. A transesterificação da (±)-mandelonitrila em agitador orbital produziu a (R)-mandelonitrila (51% ee) remanescente e o acetato da (S)-mandelonitrila (98% ee) de acordo com a regra Kazlauskas com 184 h de reação.The kinetic resolution of (±)-mandelonitrile was carried out using lipase from Candida antarctica under conventional condition (orbital shaker) and microwave irradiation in toluene, producing the (S)-mandelonitrile acetate with high selectivity (up to > 98% ee, enantiomeric excess). The unreacted (R)-mandelonitrile under microwave irradiation and conventional condition was partially converted into benzaldehyde by spontaneous chemical equilibrium. The (S)-mandelonitrile acetate under microwave irradiation was produced with 92% ee and 35% yield for 8 h of reaction. Conventional transesterification of (±)-mandelonitrile in an orbital shaker produced unreacted (R)-mandelonitrile (51% ee) and (S)-mandelonitrile acetate (98% ee) in accordance with Kazlauskas rule for 184 h of reaction.

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“…Microwave irradiation has also attracted considerable interest in recent years because of their advantages, such as reduced chemical reaction time, reduced side reactions, increased yields and improved reproducibility 2 . The objective of this study was investigate the kinetic resolution of (±)-mandelonitrile (1) using lipase from Candida antarctica under microwave irradiation and conventional conditions.…”

Section: Introductionmentioning

confidence: 99%

Influence of microwave irradiation on lipase-catalyzed kinetic resolution of (±)-mandelonitrile

Ribeiro

Oliveira²,

Porto³

2013

Proceedings of the 14th Brazilian Meeting on Organic Synthesis Proceedings

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The influence of microwave irradiation on lipase-catalyzed kinetic resolution of racemic secondary alcohols

Cited by 37 publications

References 43 publications

The influence of conventional heating and microwave irradiation on the resolution of (RS)-sec-butylamine catalyzed by free or immobilized lipases

The influence of conventional heating and microwave irradiation on the resolution of (RS)-sec-butylamine catalyzed by free or immobilized lipases

Lipase-catalyzed kinetic resolution of (±)-mandelonitrile under conventional condition and microwave irradiation

Influence of microwave irradiation on lipase-catalyzed kinetic resolution of (±)-mandelonitrile

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