This study explores halohydrin dehalogenase (HHDH) variant ISM-4 for the synthesis of enantioenriched fluorinated β-hydroxy nitrile, focusing on the reaction engineering perspective for the enhancement of process metrics. Detailed kinetic assessments, enzyme affinities, inhibitions, and deactivation dependency are integrated into a mathematical model, providing insights into ISM-4 limitations and optimal conditions for (S)-3-(4-fluorophenyl)-3-hydroxypropanenitrile’s synthesis. By strategically feeding the substrate in a fed-batch or a repetitive-batch reactor, substantial improvements are achieved compared to the batch reactor, yielding the 75 and 145 mM desired product with ee > 90 and 80%, respectively. Additionally, findings from in silico simulations guided the selection of process conditions for a reaction on a 100 mL scale in a rotating-bed reactor with an immobilized catalyst, resulting in the 24.7 mM product (Y = 72%, ee 92%). This study highlights the important role of a reaction engineering approach in enhancing HHDH-catalyzed synthesis for scalable production of valuable enantioenriched building blocks.

中文翻译：

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HHDH 催化合成对映体富集的氟化 β-羟基腈─通过反应工程方法取得工艺进展

本研究探索卤代醇脱卤酶 (HHDH) 变体 ISM-4 用于合成对映体富集的氟化 β-羟基腈，重点关注从反应工程角度增强工艺指标。详细的动力学评估、酶亲和力、抑制和失活依赖性被集成到数学模型中，从而深入了解 ISM-4 的局限性和 ( S )-3-(4-氟苯基)-3-羟基丙腈合成的最佳条件。通过在分批补料或重复分批反应器中策略性地补料底物，与分批反应器相比，实现了显着的改进，分别产生 75 和 145 mM 的所需产物，ee > 90 和 80%。此外，计算机模拟的结果指导了在具有固定催化剂的旋转床反应器中进行 100 mL 规模反应的工艺条件的选择，最终得到 24.7 mM 的产物（Y = 72%，ee 92%）。这项研究强调了反应工程方法在增强 HHDH 催化合成以大规模生产有价值的对映体富集结构单元方面的重要作用。