Biocatalysis is a branch of catalysis that exploits enzymes to perform highly stereoselective chemical transformations under mild and sustainable conditions. This Synpact highlights how biocatalysis can be used in the synthesis of chiral 1,3-mercaptoalkanols, an important class of compounds responsible for the flavours and aromas of many foods and beverages. The identification of two ketoreductase (KRED) enzymes able to reduce prochiral ketone precursors enantioselectively to 1,3-mercaptoalkanols bearing a C–O stereocentre is presented. In addition, the combination of a photocatalytic thia-Michael reaction to access prochiral ketones with subsequent KRED-biocatalysed reduction in a one-pot cascade is presented. Photo-biocatalysed cascades represent one of the new and most intriguing challenges in synthetic chemistry, because the combination of different catalytic methodologies in domino processes offers unique opportunities to outperform sequential reactions with a high degree of selectivity and the avoidance of the need to isolate reaction intermediates. 1 Introduction 2 Biocatalytic Synthesis of 1,3-Mercaptoalkanols 3 Photo-Biocatalytic Synthesis of 1,3-Mercaptoalkanols 4 Photo-Biocatalysed Cascade Reactions 5 Conclusions

中文翻译：

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用于合成挥发性硫化合物和化学构件的光生物催化级联

生物催化是催化的一个分支，它利用酶在温和和可持续的条件下进行高度立体选择性的化学转化。该 Synpact 重点介绍了如何在手性 1,3-巯基烷醇的合成中使用生物催化，这是一类重要的化合物，负责许多食品和饮料的风味和香气。介绍了两种酮还原酶 (KRED) 酶的鉴定，它们能够对映选择性地将前手性酮前体还原为带有 C-O 立体中心的 1,3-巯基链烷醇。此外，还提出了光催化硫杂-迈克尔反应获得前手性酮与随后的 KRED 生物催化还原在一锅级联中的组合。光生物催化级联反应是合成化学中新的和最有趣的挑战之一，因为多米诺过程中不同催化方法的组合提供了独特的机会，以高度的选择性和避免分离反应中间体的需要来超越顺序反应。1 引言 2 1,3-巯基烷醇的生物催化合成 3 1,3-巯基烷醇的光生物催化合成 4 光生物催化级联反应 5 结论