手性氟化胺的对映选择性合成在合成化学和制药工业中非常重要,但也极具挑战性。在此,我们建立了化学酶级联,通过有机酶脱羧氟化和双酶催化两个催化模块,在水-油-固体多相体系中从容易获得的β-酮酸酯对映选择性合成手性α-单胺和二氟甲基胺。还原胺化。通过分步酶固定化、双相系统构建和连续流操作,构建高效的连续合成系统,实现工艺强化。该流动系统实现了高达 19.7 g L –1 h –1的高时空产率与使用游离酶的批次系统相比,提高了 35 倍,并且还表现出较高的操作稳定性,96 小时后仍保持 87% 的生产活性,半衰期为 443.9 小时。
Catalytic Enantioselective Addition of an Allyl Group to Ketones Containing a Tri-, a Di-, or a Monohalomethyl Moiety. Stereochemical Control Based on Distinctive Electronic and Steric Attributes of C–Cl, C–Br, and C–F Bonds
作者:Diana C. Fager、KyungA Lee、Amir H. Hoveyda
DOI:10.1021/jacs.9b08443
日期:2019.10.9
products enantioselectively but also in some cases there are hardly any instances of a catalytic enantioselectiveaddition of a carbon-based nucleophile (e.g., one enzyme-catalyzed aldol addition involving trichloromethyl ketones, and none with dichloromethyl, tribromomethyl, or dibromomethyl ketones). The approach is scalable and offers an expeditious route to the enantioselectivesynthesis of versatile
Direct α-Fluorination of Ketones Using N-F Reagents
作者:Stojan Stavber、Marjan Jereb、Marko Zupan
DOI:10.1055/s-2002-35625
日期:——
bis(tetrafluoroborate) (Accufluor NFTh) as a fluorine atom transfer reagent and methanol as solvent enabled direct regiospecific fluorofunctionalization of the u-carbonyl position in ketones without prior activation of the target molecules. Methoxy or hydroxy substituted derivatives of 1-indanone, 1-tetralone and oxo derivatives of thiophene, benzo[b]thiophene, benzofuran and benzopyran were regiospecifically
The external quenching method based on flowmicroreactors allows the generation and use of short‐lived fluoro‐substituted methyllithium reagents, such as fluoromethyllithium, fluoroiodomethyllithium, and fluoroiodostannylmethyllithium. Highly chemoselective reactions have been developed, opening new opportunities in the synthesis of fluorinated molecules using fluorinated organometallics.
A palladium catalyzed Negishi-type α-arylation of α-fluoroketones with electron-rich and electron-deficient aryl halides or phenyl triflate has been developed. This direct mono-α-arylation method generate a variety of ternary α-aryl-α-monofluoroketones easily in good to excellent yields using XPhos as ligand and Cs2CO3 as mild base.
已经开发了钯催化的α-氟代酮的Negishi型α-芳基化反应,该反应具有富电子和电子不足的芳基卤化物或三氟甲磺酸苯酯。使用XPhos作为配体和Cs 2 CO 3作为温和的碱,这种直接的单α-芳基化方法可以轻松地以良好或优异的产率生成各种三元α-芳基-α-单氟酮。
α-Fluorotricarbonyl Derivatives as Versatile Fluorinated Building Blocks: Synthesis of Fluoroacetophenone, Fluoroketo Ester and Fluoropyran-4-one Derivatives
作者:Antal Harsanyi、Anne Lückener、Hedvig Pasztor、Zahide Yilmaz、Lawrence Tam、Dmitry S. Yufit、Graham Sandford
DOI:10.1002/ejoc.202000503
日期:2020.7.7
Fluorinated acyl‐Meldrum’s acid derivatives were synthesised by electrophilic fluorination of appropriate phenacyl Meldrum’s acid substrates using Selectfluor. Reactions with water, ethanol, Grignard and alkynyl lithium reagents gave rise to the corresponding fluoro‐acetophenone, ‐1,3‐ketoester, ‐1,3‐diketone and ‐pyran‐4‐one products respectively from the same selectively fluorinated scaffold in one‐step