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Ketone

About: Ketone is a research topic. Over the lifetime, 28264 publications have been published within this topic receiving 436250 citations. The topic is also known as: ketones.


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Journal ArticleDOI
TL;DR: The cross-coupling of organotin reagents with a variety of organic electrophiles, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond.
Abstract: The cross-coupling of organotin reagents with a variety of organic electrophiles, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond. Because this mild, versatile reaction is tolerant of a wide variety of functional groups on either coupling partner, is stereospecific and regioselective, and gives high yields of product, it is ideal for use in the synthesis of elaborate organic molecules. When the coupling reaction is carried out in the presence of carbon monoxide, instead of a direct coupling, carbon monoxide insertion takes place, stitching the two coupling partners together and generating a ketone.

2,991 citations

Journal ArticleDOI
TL;DR: The newly devised [RuCl(2)(phosphane)(2)(1,2-diamine)] complexes are excellent precatalysts for homogeneous hydrogenation of simple ketones which lack any functionality capable of interacting with the metal center.
Abstract: Hydrogenation is a core technology in chemical synthesis. High rates and selectivities are attainable only by the coordination of structurally well-designed catalysts and suitable reaction conditions. The newly devised [RuCl(2)(phosphane)(2)(1,2-diamine)] complexes are excellent precatalysts for homogeneous hydrogenation of simple ketones which lack any functionality capable of interacting with the metal center. This catalyst system allows for the preferential reduction of a C=O function over a coexisting C=C linkage in a 2-propanol solution containing an alkaline base. The hydrogenation tolerates many substituents including F, Cl, Br, I, CF(3), OCH(3), OCH(2)C(6)H(5), COOCH(CH(3))(2), NO(2), NH(2), and NRCOR as well as various electron-rich and -deficient heterocycles. Furthermore, stereoselectivity is easily controlled by the electronic and steric properties (bulkiness and chirality) of the ligands as well as the reaction conditions. Diastereoselectivities observed in the catalytic hydrogenation of cyclic and acyclic ketones with the standard triphenylphosphane/ethylenediamine combination compare well with the best conventional hydride reductions. The use of appropriate chiral diphosphanes, particularly BINAP compounds, and chiral diamines results in rapid and productive asymmetric hydrogenation of a range of aromatic and heteroaromatic ketones and gives a consistently high enantioselectivity. Certain amino and alkoxy ketones can be used as substrates. Cyclic and acyclic alpha,beta-unsaturated ketones can be converted into chiral allyl alcohols of high enantiomeric purity. Hydrogenation of configurationally labile ketones allows for the dynamic kinetic discrimination of diastereomers, epimers, and enantiomers. This new method shows promise in the practical synthesis of a wide variety of chiral alcohols from achiral and chiral ketone substrates. Its versatility is manifested by the asymmetric synthesis of some biologically significant chiral compounds. The high rate and carbonyl selectivity are based on nonclassical metal-ligand bifunctional catalysis involving an 18-electron amino ruthenium hydride complex and a 16-electron amido ruthenium species.

1,630 citations

Journal ArticleDOI
TL;DR: In the reductive amination of some aldehydes with primary amines where dialkylation is a problem, a stepwise procedure involving imine formation in MeOH followed by reduction with NaBH(4) gave consistently higher yields and fewer side products.
Abstract: Sodium triacetoxyborohydride is presented as a general reducing agent for the reductive amination of aldehydes and ketones. Procedures for using this mild and selective reagent have been developed for a wide variety of substrates. The scope of the reaction includes aliphatic acyclic and cyclic ketones, aliphatic and aromatic aldehydes, and primary and secondary amines including a variety of weakly basic and nonbasic amines. Limitations include reactions with aromatic and unsaturated ketones and some sterically hindered ketones and amines. 1,2-Dichloroethane (DCE) is the preferred reaction solvent, but reactions can also be carried out in tetrahydrofuran (THF) and occasionally in acetonitrile. Acetic acid may be used as catalyst with ketone reactions, but it is generally not needed with aldehydes. The procedure is carried out effectively in the presence of acid sensitive functional groups such as acetals and ketals; it can also be carried out in the presence of reducible functional groups such as C−C multi...

1,419 citations

Journal ArticleDOI
TL;DR: Recently, inexpensive quantitative tests of 3HB levels have become available for use with small blood samples (5–25 µl) and offer new options for monitoring and treating diabetes and other states characterized by the abnormal metabolism of ketone bodies.
Abstract: Ketone bodies are produced by the liver and used peripherally as an energy source when glucose is not readily available. The two main ketone bodies are acetoacetate (AcAc) and 3-beta-hydroxybutyrate (3HB), while acetone is the third, and least abundant, ketone body. Ketones are always present in the blood and their levels increase during fasting and prolonged exercise. They are also found in the blood of neonates and pregnant women. Diabetes is the most common pathological cause of elevated blood ketones. In diabetic ketoacidosis (DKA), high levels of ketones are produced in response to low insulin levels and high levels of counterregulatory hormones. In acute DKA, the ketone body ratio (3HB:AcAc) rises from normal (1:1) to as high as 10:1. In response to insulin therapy, 3HB levels commonly decrease long before AcAc levels. The frequently employed nitroprusside test only detects AcAc in blood and urine. This test is inconvenient, does not assess the best indicator of ketone body levels (3HB), provides only a semiquantitative assessment of ketone levels and is associated with false-positive results. Recently, inexpensive quantitative tests of 3HB levels have become available for use with small blood samples (5-25 microl). These tests offer new options for monitoring and treating diabetes and other states characterized by the abnormal metabolism of ketone bodies.

1,087 citations

Journal ArticleDOI
26 Jul 2001-Nature
TL;DR: In this paper, the Baeyer-Villiger oxidation of saturated as well as unsaturated ketones by hydrogen peroxide was investigated, and the desired lactones formed more than 98% of the reaction products.
Abstract: The Baeyer-Villiger oxidation, first reported more than 100 years ago, has evolved into a versatile reaction widely used to convert ketones-readily available building blocks in organic chemistry-into more complex and valuable esters and lactones Catalytic versions of the Baeyer-Villiger oxidation are particularly attractive for practical applications, because catalytic transformations simplify processing conditions while minimizing reactant use as well as waste production Further benefits are expected from replacing peracids, the traditionally used oxidant, by cheaper and less polluting hydrogen peroxide Dissolved platinum complexes and solid acids, such as zeolites or sulphonated resins, efficiently activate ketone oxidation by hydrogen peroxide But these catalysts lack sufficient selectivity for the desired product if the starting material contains functional groups other than the ketone group; they perform especially poorly in the presence of carbon-carbon double bonds Here we show that upon incorporation of 16 weight per cent tin into its framework, zeolite beta acts as an efficient and stable heterogeneous catalyst for the Baeyer-Villiger oxidation of saturated as well as unsaturated ketones by hydrogen peroxide, with the desired lactones forming more than 98% of the reaction products We ascribe this high selectivity to direct activation of the ketone group, whereas other catalysts first activate hydrogen peroxide, which can then interact with the ketone group as well as other functional groups

884 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023325
2022640
2021329
2020356
2019478
2018504