Unspecific peroxygenase enabled formation of azoxy compounds
Huanhuan Li, Yawen Huang, Fuqiang Chen, Zhigang Zeng, Frank Hollmann, Xin Wu, Xiyang Zhang, Peigao Duan, Hao Su, Jianjun Shi, Xiang Sheng, Wuyuan Zhang
Abstract
Enzymes are making a significant impact on chemical synthesis. However, the range of chemical products achievable through biocatalysis is still limited compared to the vast array of products possible with organic synthesis. For instance, azoxy products have rarely been synthesized using enzyme catalysts. In this study, we discovered that fungal unspecific peroxygenases are promising catalysts for synthesizing azoxy products from simple aniline starting materials. The catalytic features (up to 48,450 turnovers and a turnover frequency of 6.7 s–1) and substrate transformations (up to 99% conversion with 98% chemoselectivity) highlight the synthetic potential. We propose a mechanism where peroxygenase-derived hydroxylamine and nitroso compounds spontaneously (non-enzymatically) form the desired azoxy products. This work expands the reactivity repertoire of biocatalytic transformations in the underexplored field of azoxy compound formation reactions. Azoxy products have rarely been synthesized using enzyme catalysts. Herein, the authors report that fungal unspecific peroxygenases are promising catalysts for synthesizing azoxy products from simple aniline starting materials.