Enantiomer selective acylation of racemic alcohols by lipases in continuous-flow bioreactors

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

“…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).…”

Aminated Single-walled Carbon Nanotubes as Carrier for Covalent Immobilization of Phenylalanine Ammonia-lyase

“…6)]. A further way of process intensification is the application of the biocatalysts in continuous-flow microreactors [30]. Application of continuous-flow microreactors can significantly enhance the operational stability of immobilized biocatalysts [23].…”

“…For a comparison between the productivity of an immobilized biocatalyst in a continuous-flow reaction and in the same reaction in batch mode, the specific reaction rates should be investigated at the same degree of conversions since the rate of product formation is not a linear function of conversions [30]. The conversion of 64% (being far enough from the >90% equilibrium conversion [24]) was chosen for comparison of the batch and of the continuous-flow mode ammonia addition reactions to 2 catalyzed by SwCNT NH2 -PAL in 2 M ammonia (pH 10, at 30 °C).…”

Enzymatic resolution of tetrahydroisoquinoline derivatives in batch and continuous-flow systems

“…Thus, Poppe and co-workers reported some lipasecatalysed O-acylation reactions of the secondary alcohols 1-phenylethanol, 95 1-cyclohexylethanol, 95 1-phenylpropan-2-ol 95 and 2-methylene-substituted cycloalkanols 96 by using a CF reactor. We have found no examples of the enzymatic acylation of primary alcohols in a CF system.…”