β-unsaturated ketones. Afterward, these compounds react with different commercially available ene-reductases to afford the corresponding saturated ketones. Remarkably, in the case of trisubstituted alkenes, the bioreduction reaction occurred with high stereoselectivity. Overall, a bienzymatic one-pot two-step sequential strategy has been described with respect to the synthesis of saturated ketones starting
Focused Directed Evolution of Pentaerythritol Tetranitrate Reductase by Using Automated Anaerobic Kinetic Screening of Site-Saturated Libraries
作者:Martyn E. Hulley、Helen S. Toogood、Anna Fryszkowska、David Mansell、Gill M. Stephens、John M. Gardiner、Nigel S. Scrutton
DOI:10.1002/cbic.201000527
日期:2010.11.22
Members of the library: Multiple site‐saturated libraries of PETN reductase (shown) were screened for improved kinetic rate against a variety of poorly reduced α,β‐unsaturated activated alkenes by using an anaerobic robotics facility. Two mutants (T26S and W102F) showed a switch in product enantiopreference with substrates (E)‐2‐phenyl‐1‐nitropropene and α‐methyl‐trans‐cinnamaldehyde, respectively
文库成员:通过使用厌氧机器人设备,筛选了多个位点饱和的 PETN 还原酶文库(如图所示),以提高对各种还原程度较差的 α,β-不饱和活化烯烃的动力学速率。两个突变体(T26S 和 W102F)分别显示了与底物 ( E )-2-苯基-1-硝基丙烯和 α-甲基-反式-肉桂醛的产物对映体偏好的转换。
Reduction of Aliphatic and Aromatic Cyclic Ketones tosec-Alcohols by Aqueous Titanium Trichloride/Ammonia System. Steric Course and Mechanistic Implications
In contrast to the dissolved metal and metal hydride reductions, the reduction of cyclic ketones by the aqueous TiCl3/NH3 system favours the formation of the less thermodynamically stable axial alcohol. The ammonium ion formed in situ is essential for the reduction to proceed because it behaves as a mild Bronsted acid in basic medium and favours the protonation of the intermediate ketyl. The corresponding
Unsymmetrical 1,1-diborated multisubstituted sp<sup>3</sup>-carbons formed via a metal-free concerted-asynchronous mechanism
作者:Ana B. Cuenca、Jessica Cid、Diego García-López、Jorge J. Carbó、Elena Fernández
DOI:10.1039/c5ob01523e
日期:——
unsymmetrical 1,1-diboration of diazo compounds, formed in situ from aldehydes and cyclic and non-cyclic ketones, in the absence of any transition metal complex. The heterolytic cleavage of the mixed diboron reagent, Bpin–Bdan, and the formation of two geminal C–Bpin and C–Bdan bonds has been rationalised based on DFT calculations to occur via a concerted-asynchronous mechanism. Diastereoselection is attained
Biocatalytic C=C Bond Reduction through Carbon Nanodot‐Sensitized Regeneration of NADH Analogues
作者:Jinhyun Kim、Sahng Ha Lee、Florian Tieves、Da Som Choi、Frank Hollmann、Caroline E. Paul、Chan Beum Park
DOI:10.1002/anie.201804409
日期:2018.10.15
Light‐driven activation of redox enzymes is an emerging route for sustainable chemical synthesis. Among redox enzymes, the family of Old Yellow Enzyme (OYE) dependent on the nicotinamide adenine dinucleotide cofactor (NADH) catalyzes the stereoselective reduction of α,β‐unsaturated hydrocarbons. Here, we report OYE‐catalyzed asymmetric hydrogenation through light‐driven regeneration of NADH and its