Synthesis of α-chiral amines with high stereoselectivity and efficiency challenging. Biocatalysis have become one of the major approaches to obtain optically pure chiral amines. Many bioactive compounds such as alkaloids have more than one stereocenter and a biocatalytic cascade helps to achieve stereoselectivity throughout the synthesis of alkaloids and chiral amines. Many bioactive compounds such as alkaloids have more than one stereocenter and a biocatalytic cascade helps to achieve stereoselectivity throughout the synthesis of alkaloids and chiral amines. Herein, Mutti et al. revealed a one-pot biocatalytic system composed of ene-reductases (EReds) and imine reductases (IReds) to facilitate the stereoselective synthesis of amines with two stereocenters from α,β-unsaturated ketones (conversion rate: >99%; diastereomeric ratio: up to 99.0:1.0; enantiomeric ratio: up to >99:<1). Catalytic conversion of cyclic compounds into expanded/shrunk cyclic compounds is of great importance for pharmaceutical research. Transition metal-catalyzed ring expansion via carbon-carbon bond activation has been well-studied. N-heterocycles, especially the azetidines, are very important moieties/building blocks of biologically active compounds, which have limited synthetic options. Arnold et al. reported a novel synthesis of azetidine via onecarbon ring expansion of aziridines using engineered cytochrome P450, called P411-AzetS. 235 P411-AzetS enables highly enantioselective [1,2]-Stevens rearrangement resulting in highly enantiopure azetidine derivatives (enantiomeric ratio, 99:1).