Sattler, Johann H.5; Fuchs, Michael5; Mutti, Francesco G.5; Grischek, Barbara5; Engel, Philip5; Pfeffer, Jan6; Woodley, John M.1; Kroutil, Wolfgang5
1 Department of Chemical and Biochemical Engineering, Technical University of Denmark2 CAPEC-PROCESS, Department of Chemical and Biochemical Engineering, Technical University of Denmark3 University of Graz4 Evonik Industries AG5 University of Graz6 Evonik Industries AG
The combination of two cofactor self-sufficient biocatalytic cascade modules allowed the successful transformation of cyclohexanol into the nylon-6 monomer 6- aminohexanoic acid at the expense of only oxygen and ammonia. A hitherto unprecedented carboxylic acid capping strategy was introduced to minimize the formation of the deadend intermediate 6-hydroxyhexanoic acid. For this purpose, the precursor e-caprolactone was converted in aqueous medium in the presence of methanol into the corresponding methyl ester instead of the acid. Hence, it was shown for the first time that esterases—specifically horse liver esterase—can perform the selective ring-opening of e-caprolactone with a clear preference for methanol over water as the nucleophile.
Angewandte Chemie (international Edition), 2014, Vol 53, Issue 51