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Ezetimibe is a top‐selling hypolipidemic drug for the treatment of cardiovascular diseases. Biosynthesis of (4S)‐3‐[(5S)‐5‐(4‐fluorophenyl)‐5‐hydroxypentanoyl]‐4‐phenyl‐1,3‐oxazolidin‐2‐one ((S)‐ET‐5) using carbonyl reductase has shown advantages including high catalytic efficiency, excellent stereoselectivity, mild reaction conditions, and environmental friendness, and was considered as the key step for ezetimibe production. The regeneration efficiency of the cofactor, nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) is one of the main restricted factor. Recombinant Escherichia coli strain (smCR125) coexpressing carbonyl reductase (CR125) and glucose dehydrogenase were successfully constructed and applied for the production of (S)‐ET‐5 for the first time. Without extra addition of the coenzyme NADPH, the yield of 99.8% and the enantiomeric excess (e.e.) of 99.9% were achieved under ET‐4 concentration of 200 g/L. Using a substrate fed‐batch strategy, under the optimal conditions, the substrate ET‐4 concentration was increased to 250 g/L with the yield of 98.9% and the e.e. of 99.9% after 12 hr reaction. The space–time yield of 494.5 g L−1 d−1 and the space–time yield per gram biocatalyst of 24.7 g L−1 d−1 g−1 DCW were achieved, which were higher than ever reported for the biosynthesis of the ezetimibe intermediate. [ABSTRACT FROM AUTHOR]

As a new type of heterogeneous catalyst with "homogeneous‐like" activity, single‐site transition‐metal materials are usually treated as integrated but separate active centers. A novel grouping effect is reported for single Ni−N4 sites in nitrogen‐doped carbon (Ni/NC), where an effective ligand‐stabilized polycondensation method endows Ni/NC nanocatalysts with a high content of single‐site Ni up to 9.5 wt %. The enhanced electron density at each single Ni−N4 site promotes a highly efficient hydrogen transfer, which is exemplified by the coupling of benzyl alcohol and aniline into N‐benzylaniline with a turnover frequency (TOF) value of 7.0 molN‐benzylaniline molmetal−1 h−1; this TOF outpaces that of reported stable non‐noble‐metal‐based catalysts by a factor of 2. Herd instinct: A grouping effect is observed for single Ni−N4 sites in a Ni catalyst supported by nitrogen‐doped carbon (NC). A high 9.5 wt % Ni content was achieved with a ligand‐stabilized polycondensation method. An enhanced electron density effect manifests at each single Ni−N4 site, which decreases the binding energy of H radicals to Ni and promotes efficient coupling of benzyl alcohol and aniline to form N‐benzylaniline. [ABSTRACT FROM AUTHOR]

In this article, the synergetic effect between the B‐ and Al‐based acidic sites in B–Al co‐doped mesoporous MFI nanocrystals (denoted as m‐B‐Al‐S1) is rationally applied to modify the alcoholysis process of furfuryl alcohol. The porosity and dopant concentration of the m‐B‐Al‐S1 materials are optimized via a modified Kirkendall growth method to boost the ultra‐high selectivity to ethyl levulinate reactions (94%). The m‐B‐Al‐S1 catalyst also shows good stability for further reuses. [ABSTRACT FROM AUTHOR]