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The immobilization of Burkholderia cepacia lipase (BCL) on pristine or functionalized multiwalled carbon nanotubes (MWCNTs) was studied in the resolution of (RS)-1-phenylethanol. For the functionalization, three treatments were used, these being in H 2 SO 4 /HNO 3 (acid, MWCNTs-A), KOH (basic, MWCNTs-B) or in H 2 O 2 (oxidizing agent, MWCNTs-O). It was found that the pristine or functionalized BCL/MWCNTs resulted in a 3-fold improvement in the conversion and in a 5-fold improvement in ee s (enantiomeric excess of the substrate), when compared with free BCL under the same reaction conditions. This pristine or functionalized BCL/MWCNTs system could be reused for up to 8 times without significant decrease in the catalytic efficiency. Under the optimum conditions (pH of immobilization 6.0, 45 ºC and 25 mg/5 mg pristine or functionalized BCL/MWCNTs), the best results were obtained using BCL immobilized on MWCNTs-A. The simple process of physical adsorption of BCL onto MWCNTs-A has improved the catalytic efficiency when compared with free BCL and an increase in the stability was confirmed by thermogravimetric analysis (TGA).

O desempenho de duas lipases nativas (lipase de Aspergillus niger e Rhizopus oligosporus), e a influência da temperatura, doador acila (acetato de etila, acetato de vinila, acetato de iso-propenila e anidrido acético) e do meio orgânico foi avaliado na resolução da (RS)-feniletilamina (1). O efeito de anions em uma série de líquidos iônicos (LIs) baseados em derivados do imidazol [BMIm][X], onde X = BF 4 , PF 6 , SCN e Cl em n-heptano e acetato de vinila, também foi verificado com a lipase nativa de A. niger. Com esta lipase, a amida R-2b foi obtida com conversões de 6 até > 99% e valores de E de 2 até > 200, em n-heptano ou n-hexano. Os maiores valores de E obtidos, usando sistema bifásico formado por n-heptano e [BMIm][ PF 6 ] ou [BMIm][ BF 4 ] 9:1 (v/v), foram de 9 e 7, respectivamente, quando comparado com o solvente puro (E = 2). A influência dos ânions segue a seguinte ordem: PF 6->BF 4-> SCN-> Cl-. The performance of two native lipases (lipase from Aspergillus niger and Rhizoupus oligosporus) in the resolution of (RS)-phenylethylamine (1), varying the temperature, acyl donor type (ethyl acetate, vinyl acetate, iso-propenyl acetate and acetic anhydride) and organic medium, was studied. The effect of the nature of the anion using native A. niger lipase in n-heptane with a series of imidazolium-based ILs [BMIm][X], where X = BF 4 , PF 6 , SCN and Cl, was also evaluated. Using the lipase from A. niger, the R-2b amide was obtained with conversions from 6 to > 99% and E-values from 2 to > 200, with n-heptane or n-hexane. This lipase showed better E-values in a two-phase system using n-heptane and [BMIm][PF 6 ] or [BMIm][BF 4 ] 9:1 (v/v), obtaining values of 9 and 7, respectively, when vinyl acetate was used as the acyl donor, compared to the use of pure n-heptane (E = 2). The series for the anions in terms of decreasing performance was as follows: PF 6->BF 4-> SCN-> Cl- .

The lipase from Burkholderia cepacia (BCL) was immobilized through physical adsorption on pristine and functionalized multiwalled carbon nanotubes (MWCNTs) with carboxyl or amine groups and used in the stereoselective acylation of (R,S)‐1‐octen‐3‐ol (1) and (R,S)‐(E)‐4‐phenyl‐3‐buten‐2‐ol (4) with vinyl acetate. All immobilized preparations produced better results than free BCL. For (R,S)‐4, 50% conversion and E > 200 were obtained in n‐hexane or in solvent‐free medium. For (R,S)‐1, in solvent‐free medium, the conversion was 38% with a slight increase in the E‐value (E = 10).

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A new methodology for the synthesis of chalcogenoenynes is described. The palladium-catalyzed cross-coupling reaction of 1,2-bis(organanylchalcogeno)-alkenes and 1-alkynes gave the corresponding chalcogenoenynes in 71% to 88% yields. Preliminary pharmacologycal tests suggest that chalcogenoenynes may be useful drugs as anti-inflammatory and antinociceptive agents.