How the mode of Candida antarctica lipase B immobilization affects the continuous-flow kinetic resolution of racemic amines at various temperatures

Lipase-Catalyzed Kinetic Resolution of 1-(2-Hydroxycyclohexyl)Indoles in Batch and Continuous-Flow Systems

“…Alcohols and amines are the most thoroughly investigated substrates in KR and DKR. [29][30][31][32][33][34][35][36][37][38] The production of chiral alcohols brought in 2002 more than 7 billion dollars in revenues worldwide and this was forecasted to be 14.9 billion dollars by the year 2009. 39 Although a tremendous number of biocatalytic reactions have been studied, [16][17][18][20][21][22][23][24][25][26] the operational parameters reported for most of them seem to be rather suboptimal.…”

“…In enzymecatalysed reactions, increasing temperature generally decreases selectivity. [52][53][54][55][56][57][58][59][60][61][62] In a few studies, however, enhanced selectivity with increasing temperature, 63,64 or a maximum of enantioselectivity at a certain temperature, 38,65 or even indifference to temperature was found. 66 In most of the quoted examples, the enzyme-catalysed reactions were carried out in batch mode (in stirred or shaken flasks) and only a few studies on the temperature effects on lipase-catalysed KRs were performed in continuous-flow mode so far.…”

“…66 In most of the quoted examples, the enzyme-catalysed reactions were carried out in batch mode (in stirred or shaken flasks) and only a few studies on the temperature effects on lipase-catalysed KRs were performed in continuous-flow mode so far. 19,38,65 Herein the synthesis and lipase-catalysed kinetic resolutions of racemic 1-(2-hydroxycyclohexyl)indoles (rac-2a-c) are reported in both batch and continuous-flow systems (Scheme 1). According to our best knowledge, these are the first KRs of the already known (rac-2a) and of the novel trans-1-(2-hydroxycyclohexyl)indoles (rac-2b and rac-2c).…”

Immobilization of lipases from Rhizomucor miehei and Thermomyces lanuginosus by adsorption on variously grafted silica gels

“…the Cross-Linked Enzyme Aggregate (CLEA) or Immobead 150 variants of TlL or RmL from Sigma-Aldrich], studies with variously immobilized forms of CaLB [13,17] indicated that hydrophobic adsorption on a modified surface might result in useful biocatalysts. Therefore, the adsorptive immobilization of lipases from Rhizomucor miehei and Thermomyces lanuginosus (RmL and TlL) was performed as described earlier for CaLA and CaLB [12] as well as for Lipase AK and Lipase PS [17].…”

“…Among the many available immobilization methods, including adsorption, covalent attachment to solid supports and entrapment within polymers [8][9][10][11], hydrophobic adsorption onto suitable carriers was found to be an efficient way not only for immobilization but also for the separation of lipases [12]. Lipases immobilized by various procedures proved to be useful both in batch mode and in continuous-flow biotransformations [13][14][15][16].…”