Microbial hydrolysis of substituted mandelonitrile acetates and its application to the synthesis of optically active physiological ethanolamines.

Formation of Optically Active Aryloxyacetaldehyde Cyanohydrin Acetates with the Aid of a Microorganism

“…9 ) Thus, the effect of the structure of the acid part of phenoxyacetaldehyde cyanohydrin esters have been examined. As summarized in Table VI, propionate (10) and isobutyrate (11) also gave Table VI, both propionate and isobutyrate had high optical purity. In conclusion, the esterase of B. coagulans can be successfully applied to the asymmetric hydrolysis of a number of aryloxyacetaldehyde cyanohydrin esters, which are useful as the chiral intermediates for the synthesis of physiologically active p-adrenergic blocking agents.…”

High‐Throughput Preparation of Optically Active Cyanohydrins Mediated by Lipases

“…Optically active cyanohydrins can be prepared either by asymmetric catalysis – mediated by metal–organic frameworks or metal complexes – or by biocatalytic methods based on the use of oxynitrilases or peptide‐based catalysts . Another relevant way to achieve the synthesis of optically active cyanohydrins uses lipase‐mediated kinetic resolution (EKR) reactions, which can be carried out through the acylation of cyanohydrins (Scheme , A) or by hydrolysis/alcoholysis of cyanohydrin esters (Scheme , B), in both cases with classical or dynamic resolution …”

“…Several examples of EKR reactions involving cyanohydrins have already been described. These involve acylation by Burkholderia cepacia and Candida antarctica lipase B; hydrolysis by Bacillus coagulans , Bacillus licheniformis , Candida rugosa , Pseudomonas aeruginosa , metagenome‐derived esterases, and several other proteases; alcoholysis by Candida antarctica lipase A, Candida antarctica lipase B, Candida rugosa , and Pseudomonas fluorescens ; and aminolysis by Candida antarctica lipase A . The published results indicate that, depending on the substrate structure, although good enantioselectivities can be achieved, long reaction times can be required to reach these high enantiomeric excesses.…”