114829-07-1

Visible light promoted fluoroalkylation of hydrazones using 4-perfluoropyridine sulfides as fluoroalkyl radical sources is described. The process can proceed in neutral and reductive modes delivering either hydrazones or hydrazines, respectively, depending on structure of starting substrates and reaction conditions. For the reductive process, ascorbic acid is used as a terminal reductant, which recycles the photocatalyst and serves as a source of hydrogen towards nitrogen-centered radicals. (Figure presented.).

CF2H groups are unique due to the combination of their lipophilic and hydrogen bonding properties. The strength of H-bonding is determined by the group to which it is appended. Several functional groups have been explored in this context includ

Transaminases have shown the ability to catalyze the amination of a series of aliphatic and (hetero)aromatic α,α-difluorinated ketones with high stereoselectivity, thus providing the corresponding β,β-difluoroamines in high isolated yields (55–82%) and ex

The difluoromethyl (CHF2) group has attracted significant attention in drug discovery and development efforts, owing to its ability to serve as fluorinated bioisostere of methyl, hydroxyl, and thiol groups. Herein, we report an efficient biocat

The continuous flow reaction of various aryl or heteroaryl bromides in toluene in the presence of THF (1.0 equiv) with sec-BuLi (1.1 equiv) provided at 25 °C within 40 sec the corresponding aryllithiums which were acylated with various functionalized N,N-

A simple and straightforward approach to the synthesis of trifluoromethyl and difluoromethyl ketones from widely available carboxylic acids is disclosed. The transformation utilizes an acyloxyphosphonium ion as the active electrophile, conveniently generated in situ from the carboxylic acid substrate by using commodity chemicals. The utility of the reaction system is exemplified by its chemoselectivity, with tolerance to a variety of important functional groups. The late-stage functionalization of carboxylic acid active pharmaceutical ingredients and pharmaceutically relevant compounds is also discussed.

Fluoroalkyl alcohols are effectivity oxidized to the corresponding fluoroalkyl carbonyl compounds by reaction with sodium hypochlorite pentahydrate in acetonitrile in the presence of acid and nitroxyl radical catalysts. Although the reaction proceeded slower under a nitroxyl radical catalyst- free condition, the desired carbonyl compounds were obtained in high yields. For the reaction with fluoroalkyl allylic alcohols, the corresponding α,β-epoxyketone hydrates were obtained in high yields.

A palladium-catalyzed fluoroacylation of (hetero)aryl boronic acid with the fluorothioacetates is described at ambient temperature. A variety of aryl, and heteroaryl boronic acids are compatible in the reaction, affording the corresponding fluoroalkyl ketones in moderate to good yields. Further late-stage di-, and trifluoroacylation of drug molecule clofibrate and estrone demonstrated the synthetic practicability of this protocol.2009 Elsevier Ltd. All rights reserved.

The homologation of Weinreb amides into difluoromethylketones with a formal nucleophilic CHF2 transfer agent is reported. Activating TMSCHF2 with potassium tert-amylate enables a convenient access to the difluorinated homologation re

The invention belongs to the field of pharmaceutical and chemical intermediates and relative chemical technologies. N-phenyl-N-p-toluenesulfonyl difluoroacetamide and application thereof are disclosed. Under the action of a metal catalyst, a ligand and alkali, N-phenyl-N-p-toluenesulfonyl difluoroacetamide, which is used as a difluoroacetylation reagent, reacts with an arylboronic acid compound inan organic solvent to be efficiently and highly selectively converted into a difluoroacetophenone compound. The synthetic method of the difluoroacetophenone compound has few reaction steps, is environmentally-friendly by using stable, easily-stored and cheap and easily-available NDFTS as the difluoroacetyl source, has mild reaction condition, and is convenient to operate; and since the target product is obtained with high yield and high selectivity, the synthetic method has good industrial production value and practical application value. The difluoroacetophenone compound synthesized by the method can be further subjected to a functionalization reaction and is widely applied in the fields of medicine, pesticide, bioactive molecule and functional material molecule synthesis.

The invention discloses a synthesis method of JAK inhibitor intermediates. The method comprises the steps that a compound (2) serves as the raw material and reacts with ethylboric acid in the presenceof a catalyst, sodium phosphate and a phase transfer ca

A one-step protocol for the difluoromethylation of carboxylic acids is described. The reaction involves the interaction of intermediate acyl chlorides with in situ generated difluorinated phosphorus ylide Ph3P=CF2. Aromatic acids can be selectively transformed within one step either to bis-difluoromethylated alcohols or to difluorinated ketones depending on the particular reaction conditions. For bulky α-branched carboxylic acids, only ketones are produced.

The first catalytic asymmetric synthesis of highly functionalized difluoromethylated cyclopropanes is described. The method, based on a rhodium-catalyzed cyclopropanation of difluoromethylated olefins, gives access to a broad range of cyclopropanes bearing ester, ketone, or nitro functional groups. By using Rh2((S)-BTPCP)4 as a catalyst, the corresponding products were obtained in high yields and high diastereo- and enantioselectivities (up 20:1 d.r. and 99 % ee). This methodology allowed preparation of enantioenriched difluoromethylcyclopropanes for the first time.

A facile synthetic approach to a series of difluoromethyl ketones from β-ketoacids has been described. This transformation is achieved through the straightforward decarboxylative difluorination of β-ketoacids in the absence of any catalyst. Furthermore, the resulted difluoromethyl ketones can be easily converted into corresponding difluoromethylated building blocks for pharmaceuticals and materials. (Figure presented.).

Difluoromethyl ketones are an under-studied class of ketones which have great potential as useful building blocks for materials and drug design. Here we report a simple and convenient synthesis of this class of compounds via a one-pot difluorination/fragm

The use of TFEDMA, a fluoroalkyl amino reagent, for the difluoromethylation and difluoroacylation of arenes, heteroarenes, and C-H acidic compounds is reported. This approach allows for an efficient access to difluoromethylated products of high added valu

The synthetic utility of α,α-difluoro-α-phenylsulfanyl- α-trimethylsilylmethane (PhSCF2SiMe3; 1) as a difluoromethyl building block providing a general strategy to α,α-difluoromethyl aryl ketones was demonstrated. Oxidation, by using

A two-step, one-pot microwave (MW) assisted fluorination of 1-arylethanones to their corresponding 1-aryl-2-fluoroethanones has been developed. The first step utilises Selectfluor as a fluorinating agent in methanol forming 1-aryl-2-fluoroethanones and their corresponding dimethyl acetals. In the second step, water is added and Selectfluor acts as a Lewis acid in the hydrolytic cleavage of the dimethyl acetals. Compared to the thermal synthesis, the MW assisted method leads to a reduction in reaction time both in the fluorination and for the dimethyl acetal cleavage. Moreover, the one-pot procedure reduces reagent and solvent consumption. The method is best suited for the preparation of 1-aryl-2-fluoroethanones containing substituents that deactivates electrophilic aromatic substitution, however highly electron deficient ketones such as 1-(3,5-dinitrophenyl)ethanone reacts more slowly. Reactions using electron rich aromatic ketones had a low regioselectivity, and also produced fluoroaromatic products.

1-Aryl-2,2-difluoro enol benzoates 4 has been prepared from α-(phenylsulfonyl)-difluoromethylated benzoates 3, which can be readily obtained from the reactions between simple aldehydes and PhSO2CF2H (or TMSCF2SO2/sub

The regioselective palladium-catalyzed formate reduction of γ-fluoroalkylated allylic esters is described. Reduction of the allylic esters under the influence of palladium with a monodentate phosphine ligand proceeded preferentially at the γ position, the corresponding reduction products with a fluoroalkyl group at the tertiary carbon being afforded in high yields. When the chiral allylic ester was employed, complete chirality transfer was observed, leading to the optically active materials in high yields.

Selective and efficient synthesis of α,α-difluoro ketones was achieved following a protocol which includes the transformation of α-methylene ketones to the corresponding n-butylimine derivatives and their further treatment with Selectfluor F-TEDA-BF4

Reactions of enamines, preformed from β-dicarbonyl and monocarbonyl compounds, with Selectfluor (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2] octane bis(tetrafluoroborate) under mild conditions (triethylamine (TEA) or molecular sieves) easily led to the corresponding difluorinated carbonyl compounds in high yields.

Direct fluorination of imines with N-fluoro-bis[(trifluoromethyl)sulfonyl]imide 1 afforded mono and/or difluoroketones without the need of a strong base to first generate the imine anions. Structurally related 2- and 4-methyl-substituted pyridines gave the respective fluoromethyl pyridines with 1. Our results suggest that an enamine intermediate plays a key role in these reactions.

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