摘要：Ádám Dudás, Ádám Gyömöre, Bence Balázs Mészáros, Stefánia Gondár, Renáta Adamik, Dániel Fegyverneki, Dávid Papp, Konrad Bernhard O
转自：康龙化成
Selective Reduction of Esters to Access Aldehydes Using Fiddler Crab-Type Boranes
Ádám Dudás, Ádám Gyömöre, Bence Balázs Mészáros, Stefánia Gondár, Renáta Adamik, Dániel Fegyverneki, Dávid Papp, Konrad Bernhard Otte,Sergio Ayala Jr., János Daru, József Répási,Tibor Soós*
[a] Organocatalysis Research Group, Institute of Organic Chemistry, HUN-REN Research Centre forNatural Sciences, Magyar tudósok körútja 2,Budapest H-1117, Hungary;
[b] Hevesy György PhD School of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A,Budapest H-1117, Hungary;
[c] Provivi,Inc., Santa Monica, California 90404, United States;
[d]Department of Organic Chemistry, Eötvös Loránd University, Budapest H-1117, Hungary;
[e] AldexchemLtd., É rdH-2030, Hungary
—J.Am. Chem. Soc. 2024, doi: 10.1021/jacs.4c14596
Recommended by Depei Meng_MC4
KEYWORDS: ester reduction(反应类型),C(O)–H (成键类型),ester (原料),aldehyde (产物), Et3SiH (还原剂), Fiddler Crab-Type Boranes (催化剂)
ABSTRACT: Thepartial reduction of esters to aldehydes is a fundamentally importanttransformation for the synthesis of numerous fine chemicals and consumer goods.However, despite the many efforts, limitations have persisted, such ascompeting over reduction, low reproducibility, use of exigent reactionconditions and hazardous chemicals. Here, we report a novel catalyst familywith a unique steric design which promotes the catalytic partial reduction ofesters with unprecedented, near-perfect selectivity and efficiency. Thismetal-free catalytic method is ready to be placed at the disposal of chemiststo provide valuable aldehyde intermediates and products and shows promise forstreamlining synthetic methods in academic and industrial settings.
Methods to access aldehydes and catalystdesign for near-perfect selectivity in partial ester reduction
Scope and limitations of the near-perfectselective ester hydrosilylation
Selectedapplications of the catalytic hydrosilylation methodology
Overall,this metal-free catalytic reduction canbe conducted and easily scaled up at ambient temperature, without asolvent, using low catalyst loads and commercially available andinexpensive reducing agents.In addition to their high catalytic activity and selectivity, the appliedcatalysts are tolerant to various functional groups, and most importantly,exhibit exclusive selectivity which often obviates the need for chromatographyto separate side products. Accordingly, this metal-free method not onlyapproximates, but exceeds the activity/selectivity bar set by firmlyestablished transition metal catalysts.
总的来说，这种无金属催化的还原反应可以在室温下进行，并且可以容易地在无溶剂、低催化剂负载量和市售廉价还原剂的条件下进行放大。催化剂(FiddlerCrab-Type Boranes)不仅具有高催化活性和选择性，还对各种官能团具有耐受性，最重要的是，其独特的选择性使得通常不需要色谱法来分离副产物。也因此，这种无金属方法展现了接近、甚至超过过渡金属催化条件的活性/选择性水平。
来源：新浪财经
