A modern concept of producing nitriles involves aldoxime dehydratases, which are capable of dehydrating aldoximes to the corresponding nitriles without need of a cofactor. Aldoximes as the starting material for nitrile synthesis are easily prepared by condensation of hydroxylamine with the corresponding aldehydes. In this contribution we present chemoenzymatic cascade reactions toward nitriles consisting of an initial nitroxyl radical-catalyzed oxidation of aliphatic alcohols to aldehydes using sodium hypochlorite as the oxidation agent, subsequent condensation of the aldehyde with hydroxylamine, and a biocatalytic dehydration using aldoxime dehydratases to the corresponding nitriles without isolation of intermediates and using the product nitrile as a solvent. These formal “solvent-free” cascades open up the possibility to use biorenewable sources, namely fatty acids, as the starting material for a chemoenzymatic nitrile synthesis. We were also able to apply this cascade concept for the synthesis of aliphatic dinitriles, which are used as, e.g., a precursor for polymer building blocks. Overall yields without isolation of intermediates of up to 70% with very simple product isolation were achieved.

中文翻译：

---

从生物可再生原料开始向脂肪腈的化学酶联反应

生产腈的现代概念涉及醛肟脱水酶，其能够将醛肟脱水成相应的腈而无需辅因子。羟胺与相应的醛缩合可轻松制备作为腈合成原料的醛肟。在这一贡献中，我们提出了对腈的化学酶联反应，包括使用次氯酸钠作为氧化剂，将脂肪醇初步氧化为脂肪族醇，然后由腈氧基自由基氧化为醛，随后醛与羟胺缩合，然后使用醛肟脱水酶将其生物催化脱水成相应的醛。腈无需分离中间体，并使用腈产品作为溶剂。这些正式的“无溶剂”级联打开了使用生物可再生资源（即脂肪酸）作为化学酶腈合成原料的可能性。我们也能够将这种级联概念应用到脂肪族二腈的合成中，该脂肪族二腈用作例如聚合物构件的前体。通过非常简单的产品分离，无需分离中间体即可获得高达70％的总收率。