Frontispiece: Mechanistic Study of the Stereoselective Hydroxylation of [2‐2H1,3‐2H1]Butanes Catalyzed by Cytochrome P450 BM3 Variants

Catalytic mechanism of cytochrome P450 A high H/D kinetic isotope effect (KIE) (18–25) is observed from the hydroxylation of tailored di‐deuterated butane substrate, (2S,3S)‐[2‐2H1,3‐2H1]butane, mediated by engineered cytochrome P450 BM3. For the first time, the experimental evidence that supports the participation of quantum tunneling at the secondary C–H bond oxidized by P450 BM3 is demonstrated. This mechanistic revelation provides the basis for the development of biomimetic iron based catalysts for small alkane oxidation or the process for “gas‐to‐liquid” (GTL) conversion. For more information, see the Full Paper by S. Yu et al. on page 2571 ff.