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
Catalytic carbonyl hydrosilylations via a titanocene borohydride–PMHS reagent system
作者:Godfred D. Fianu、Kyle C. Schipper、Robert A. Flowers II
DOI:10.1039/c7cy01088e
日期:——
Reduction of a wide range of aldehydes and ketones with catalytic amounts of titanocene borohydride in concert with a stoichiometric poly(methylhydrosiloxane) (PMHS) reductant is reported. Preliminary mechanistic studies demonstrate that the reaction is mediated by a reactive titanocene(III) complex, whose oxidation state remains constant throughout the reaction.
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
Enantio- and regioselective <i>ene</i>-reductions using F<sub>420</sub>H<sub>2</sub>-dependent enzymes
作者:Sam Mathew、Milos Trajkovic、Hemant Kumar、Quoc-Thai Nguyen、Marco W. Fraaije
DOI:10.1039/c8cc04449j
日期:——
In the past decade it has become clear that many microbes harbor enzymes that employ an unusual flavin cofactor, the F420 deazaflavin cofactor. Herein we show that F420-dependent reductases (FDRs) can successfully perform enantio-, regio- and chemoselective ene-reductions. For the first time, we have demonstrated that F420H2-driven reductases can be used as biocatalysts for the reduction of α,β-unsaturated
在过去的十年中,很明显,许多微生物都带有使用不常见的黄素辅助因子F 420去氮黄素辅助因子的酶。本文中,我们显示了依赖F 420的还原酶(FDR)可以成功地进行对映体,区域和化学选择性烯的还原。首次,我们证明了F 420 H 2驱动的还原酶可用作生物催化剂,以良好的转化率(> 99%)以及优异的区域选择性和对映体过量(> 99)还原α,β-不饱和酮和醛。 %ee)。值得注意的是,与公认的FMN依赖的旧黄色酶(OYE)相比,FDR通常显示相反的对映选择性。
Asymmetric Bioreduction of CC Bonds using Enoate Reductases OPR1, OPR3 and YqjM: Enzyme-Based Stereocontrol
Three cloned enoate reductases from the “old yellow enzyme” family of flavoproteins were investigated in the asymmetricbioreduction of activatedalkenes. 12-Oxophytodienoatereductaseisoenzymes OPR1 and OPR3 from Lycopersicon esculentum (tomato), and YqjM from Bacillus subtilis displayed a remarkably broad substrate spectrum by reducing α,β-unsaturated aldehydes, ketones, maleimides and nitroalkenes