Discovery of a P450-Catalyzed Oxidative Defluorination Mechanism toward Chiral Organofluorines: Uncovering a Hidden Pathway
Qun Huang, Xuan Zhang, Qianqian Chen, Shaixiao Tian, Wei Tong, Wei Zhang, Yingzhuang Chen, Ming Ma, Bo Chen, Binju Wang, Jian‐bo Wang
Abstract
While the enzymatic oxidative cleavage of C–F bonds at achiral centers catalyzed by P450 monooxygenases has been studied extensively, less is known about the oxidative defluorination mechanism of chiral substrates with fluorine being at chirality centers. Here, we report that the use of ethyl 2-fluoro-2-phenylacetate as a stereochemical probe enabled us to discover two oxidative defluorination paths catalyzed by P450-BM3: α-site hydroxylation and hydroxylation at the remote phenyl group. By means of intermediate identification and capture, chemical mimics, key intermediate derivatization, and deuterium insertion experiments as well as QM theoretical calculations, we succeeded in demonstrating an unusual mechanism in which these two oxidative defluorination routes occur in a P450 monooxygenase. This work presents valuable insights into the oxidative degradation of organofluorines and provides a convenient method for remote C–F bond activation.