31366-07-1

Activation of the neuropeptide S receptor (NPSR) system has been shown to produce an-xiolytic-like actions, arousal, and enhance memory consolidation, whereas blockade of the NPSR has been shown to reduce relapse to substances of abuse and duration of anesthetics. We report here the discovery of a novel core scaffold (+) N-benzyl-3-(2-methylpropyl)-1-oxo-3-phenyl-1H,3H,4H,5H,6H,7H-furo[3,4-c]pyridine-5-carboxamide with potent NPSR antagonist activity in vitro. Pharmacokinetic parameters demonstrate that 14b reaches pharmacologically relevant levels in plasma and the brain following intraperitoneal (i.p.) administration, but is cleared rapidly from plasma. Compound 14b was able to block NPS (0.3 nmol)-stimulated locomotor activity in C57/Bl6 mice at 3 mg/kg (i.p.), indicating potent in vivo activity for the structural class. This suggests that 14b can serve as a useful tool for continued mapping of the pharmacological functions of the NPS receptor system.

The invention provides a method for synthesizing an aryl ketone compound by taking AQ as a photocatalyst. The method comprises the following steps that AQ serves as a photocatalyst; under the conditions of a palladium catalyst, a phosphine ligand, weak base and an organic solvent, a 390-to-430-nm photocatalysis lamp is used for irradiation at room temperature in an inert protective atmosphere, soan aldehyde group-containing compound reacts with Ar-X, wherein Ar-X is aryl halide or aryl trifluoromethanesulfonic acid, the aryl halide is aryl bromide or aryl iodide, and the aldehyde group-containing compound is one selected from aryl aldehyde, alkyl aldehyde, linear primary aldehyde and acyclic secondary aldehyde. According to the invention, the anthraquinone (AQ) HAT photocatalyst and palladium catalyst are combined for use, C-H arylation and alkenylation reactions of aldehyde can be directly carried out to synthesize ketone, and reaction efficiency is high. The method has the advantages of mild reaction conditions, high yield and a wide substrate application range, and can be used for synthesizing natural products in medicinal plants.

Herein, we report that merging palladium catalysis with hydrogen atom transfer (HAT) photocatalysis enabled direct arylations and alkenylations of aldehyde C-H bonds, facilitating visible light-catalyzed construction of a variety of ketones. Tetrabutylammonium decatungstate and anthraquinone were found to act as synergistic HAT photocatalysts. Density functional theory calculations suggested a Pd0-PdII-PdIII-PdI-Pd0 pathway and revealed that regeneration of the Pd0 catalyst and the photocatalyst occurs simultaneously in the presence of KHCO3. This regeneration features a low energy barrier, promoting efficient coupling of the palladium catalytic cycle with the photocatalytic cycle. The work reported herein suggests great promise for further applications of HAT photocatalysis in palladium-catalyzed cross-coupling and C-H functionalization reactions to be successful.

We report herein that a palladium catalyst in combination with a dual phosphine ligand system catalyzes alkylation of silyl enol ether and enamide with a broad scope of tertiary, secondary, and primary alkyl bromides under mild irradiation conditions by blue light-emitting diodes. The reactions effectively deliver α-alkylated ketones and α-alkylated N-acyl ketimines, and it is difficult to prepare the latter by other methods in a stereoselective manner. The α-alkylated N-acyl ketimine products can be further subjected to chiral phosphoric acid-catalyzed asymmetric reduction with Hantzsch ester to deliver chiral N-acyl-protected α-arylated aliphatic amines in high enantioselectivity up to 99% ee, thus providing a method for facile synthesis of chiral α-arylated aliphatic amines, which are of importance in medicinal chemistry research. The N-acetyl ketimine product also reacted smoothly with various types of Grignard reagents to afford sterically bulky N-acetyl α-tertiary amines in high yields. Theoretical studies in combination with experimental investigation provide understanding of the reaction mechanism with respect to the dual ligand effect and the irradiation effect in the catalytic cycle. The reaction is suggested to proceed via a hybrid alkyl Pd(I)-radical species generated by inner-sphere electron transfer of phosphine-coordinated Pd(0) species with alkyl bromide. This intriguing hybrid alkyl Pd(I)-radical species is elucidated by theoretical calculation to be a triplet species coordinated by three phosphine atoms with a distorted tetrahedral geometry, and spin prohibition rather than metal-to-ligand charge transfer contributes to the kinetic stability of the hybrid alkyl Pd(I)-radical species to impede alkyl recombination to generate Pd(II) alkyl intermediate.

The application relates to a alkaline cage compound, its preparation method and catalyst. The application of the alkaline cage compound, containing 6 has a strong alkaline secondary amine group of Soluble in many common organic solvent (such as ethyl acet

A convenient Fe-catalyzed decarbonylative alkylation-peroxidation of alkenes with aliphatic aldehydes and TBHP to provide chain elongated peroxides is developed, which is further applied to the one-pot synthesis of alkylated ketones. Aliphatic aldehydes were decarbonylated into 1°, 2° and 3° alkyl radicals at low temperature which subsequently allows the cascade construction of C(sp3)-C(sp3) and C(sp3)-O bonds via radical insertion and radical-radical coupling. Various alkenes including mono-substituted, terminally disubstituted or internally disubstituted styrenes bearing synthetically useful functional groups and electron-poor acrylates were tolerated.

A new catalytic method is described to access carbocation intermediates via the mesolytic cleavage of alkoxyamine radical cations. In this process, electron transfer between an excited state oxidant and a TEMPO-derived alkoxyamine substrate gives rise to a radical cation with a remarkably weak C?O bond. Spontaneous scission results in the formation of the stable nitroxyl radical TEMPO.as well as a reactive carbocation intermediate that can be intercepted by a wide range of nucleophiles. Notably, this process occurs under neutral conditions and at comparatively mild potentials, enabling catalytic cation generation in the presence of both acid sensitive and easily oxidized nucleophilic partners.

The copper-catalyzed addition of bis(pinacolato)diboron to internal alkynes in the presence of methanol generates alkenylboron compounds with high levels of regio- and stereoselectivities. The catalytic efficiency is increased by using monodentate phosphine ligands, especially P(p-tolyl)3 and a range of internal alkynes was borylated in good yields. The Royal Society of Chemistry.

(Chemical Equation Presented) An efficient methodology for the indirect anti-Markovnikov hydration of unsymmetrically substituted terminal and internal alkynes is based on TiCl4-catalyzed hydroamination reactions. Its application to ortho-alkynylhaloarenes, followed by a copper-catalyzed O-arylation, provides flexible access to substituted benzo[b]furans.

The radical alkylation of ketones is achieved by their conversion into corresponding N-silyloxy enamines, followed by a radical reaction with alkyl halides bearing electron-withdrawing groups. The Royal Society of Chemistry 2006.

α-tert-Butoxystyrene [H2C = C(OBut)Ph] reacts with α-bromocarbonyl or α-bromosulfonyl compounds [R 1R2C(Br)EWG; EWG = -C(O)X or -S(O2)X] to bring about replacement of the bromine atom by the phenacyl group and give R 1R2C(EWG)CH2C(O)Ph. These reactions take place in refluxing benzene or cyclohexane with dilauroyl peroxide or azobis(isobutyronitrile) as initiator and proceed by a radical-chain mechanism that involves addition of the relatively electrophilic radical R 1R2(EWG)C* to the styrene. This is followed by β-scission of the derived α-tert-butoxybenzylic adduct radical to give But*, which then abstracts bromine from the organic halide to complete the chain. α-1-Adamantoxystyrene reacts similarly with R 1R2C(Br)EWG, at higher temperature in refluxing octane using dα-tert-amyl peroxide as initiator, and gives phenacylation products in generally higher yields than are obtained using α-tert-butoxystyrene. Simple iodoalkanes, which afford relatively nucleophilic alkyl radicals, can also be successfully phenacylated using α-1-adamantoxystyrene. O-Alkyl O-(tert-butyldimethylsilyl) ketene acetals H2C=C(OR)OTBS, in which R is a secondary or tertiary alkyl group, react in an analogous fashion with organic halides of the type R1R2C(Br)EWG to give the carboxymethylation products R1R2C(EWG)CH 2CO2Me, after conversion of the first-formed silyl ester to the corresponding methyl ester. The silyl ketene acetals also undergo radical-chain reactions with electron-poor alkenes to bring about alkylation-carboxymethylation of the latter. For example, phenyl vinyl sulfone reacts with H2C=C(OBut)OTBS to afford Bu tCH2CH(SO2Ph)CH2CO2Me via an initial silyl ester. In a more complex chain reaction, involving rapid ring opening of the cyclopropyldimethylcarbinyl radical, the ketene acetal H 2C=C(OCMe2C3H5-cyclo)OTBS reacts with two molecules of N-methyl- or N-phenyl-maleimide to bring about [3 + 2] annulation of one molecule of the maleimide, and then to link the bicyclic moiety thus formed to the second molecule of the maleimide via an alkylation-carboxymethylation reaction.

The Ru3(CO)12-catalyed cross-coupling reaction of esters with organoboron compounds leading to ketones is described. A wide variety of functional groups can be tolerated under the reaction conditions. Aromatic boronates function as a coupling partner to give aryl ketones. Acyl-alkyl coupling to dialkyl ketones is also achieved by the use of 9-alkyl-9-BBN in place of boronates. The Ru3(CO)12- catalyzed decarbonylative reduction of esters with ammonium formate (HCOONH 4) leading to hydrocarbons is also described. No expected aldehydes are produced, and controlled experiments indicate that aldehydes are not intermediate for the transformation. A hydrosilane can also be used as a reducing reagent in place of HCOONH4. A wide variety of functional groups are compatible for both reactions. The key step for both catalytic reactions is the directing group-promoted cleavage of an acyl carbon-oxygen bond in esters, leading to the generation of acyl transition metal alkoxo complexes.

Terminal alkenes of the type H2C=C(OR1)X, in which R1 is a tertiary alkyl or a 1-cyclopropylethyl group and X=Ph, OSiMe2But, OEt or H, undergo radical-chain reactions with organic halides R2Hal to give carbonyl compounds R2CH2C(=O)X.

(Equation presented) The radical-initiated β-ketoalkylation of haloalkanes with tributylstannyl enolates is described. Stannyl enolates derived from aromatic ketones are reactive toward the homolytic β-ketoalkylation of simple haloalkanes as well as those activated by an electron-withdrawing group. The reactivity of stannyl enolates as radical alkylating agents can be utilized for an efficient three-component coupling reaction among stannyl enolates, haloalkanes, and electron-deficient alkenes.

Phenyldimethylsilyllithium reacts with acyloin silyl ethers RCH(OSiMe3)COR 8 to give regiodefined silyl enol ethers RCH=C(OSiMe2Ph)R 9, and hence by hydrolysis ketones RCH2COR 10. The yields can be high but are usually moderate. The mechanism of this reduction is established to involve a Brook rearrangement (Scheme 6) rather than a Peterson elimination (Scheme 1). Although the mechanism appears to be the same in each case, the stereochemistries of the silyl enol ethers 9 are opposite in sense in the aromatic series (R = Ph, Scheme 7) and the aliphatic series (R = cyclohexyl, Scheme 8), with the major aromatic silyl enol ether being the thermodynamically less stable isomer E-PhCH=C(OSiMe2Ph)Ph E-9aa, and the major aliphatic silyl enol ether being the thermodynamically more stable isomer Z-c-C6H11CH= C(OSiMe2Ph)-c-C6H11 Z-9ba. This is a consequence of anomalous anti-Felkin attack in the aromatic series. The reaction with the silyl ether ButCH(OSiMe3)COPh 13b is normal in giving Z-ButCH= C(OSiMe2Ph)Ph Z-38 (Scheme 11), but reduction of the silyl ether 8a with lithium aluminium hydride is also anti-Felkin giving with high selectivity the meso diol PhCH(OH)CH(OH)Ph 39. The reaction between Phenyldimethylsilyllithium and the acyloin silyl ether 8d (R = But) does not give the ketone ButCH2COBut, but gives instead the anti-Felkin meso diol ButCHOHCHOHBut 40 also with high selectivity (Scheme 12). Silyllithium and some related reagents react with trifluoromethyl ketones 46 and 48 to give α,α-difluoro silyl enol ethers 47 and 49 (Scheme 14).

α-Alkoxyalkenylstannanes prepared by the Pd0-catalysed hydrostannylation of 1-alkoxyalk-1-ynes, undergo Pd0-catalysed Stille-type cross-coupling reactions with acid chlorides, aryl iodides and alkenyl trifluoromethanesulfonates.In the most complex case, an enol ether moiety was appended to a carbapenem nucleus.The coupling reaction was strongly dependent upon solvent, temperature, and added ligands.The method substantially extends the use of metallated enol ethers as nucleophilic acylation agents.

The use of appropriately prepared silica gel and alumina has been found to mediate the addition of hydrogen halides to alkynes.The technique has been rendered even more convenient by the use of various organic and inorganic acid halides that react in the presence of silica gel or alumina to generate hydrogen halides in situ.Treatment in this fashion of 1-propynylbenzene (1), which underwent no reaction in CH2Cl2 solution saturated with HCl, readily afforded the syn addition product, alkenyl chloride (E)-4a.On extended treatment (E)-4a underwent subsequent iaomerization to the thermodynamically more stable Z isomer.Thus either isomer of 4a could be obtained in good yield depending on the reaction conditions.In a similar way bromides (E)- and (Z)-4b were obtained without competing formation of the radical products (E)- and (Z)-5, which occurred in solution.In contrast with solution-phase hydroiodination of alkyne 1, which slowly afforded iodide (E)-4c, surface-mediated addition readily afforded (E)-4c, followed by isomerization to the Z isomer.E ->/- Z equilibration of the alkenyl halides 4 was shown to involve, at last in part, addition-elimination via the gem-dihalides 13.Analogous behavior was exhibited by the phenylalkynes 2 and 3 on surface-mediated hydrohalogenation.Surface-mediated addition of HBr and HI to the internal alkylalkyne 14 afforded principally the anti addition products (Z)-15b,c.Treatment of the terminal alkynes 17 and 22 with (COBr)2 over alumina gave the dibromides 20 and 24/25, respectively, whereas use of acetyl bromide as the HBr precursor afforded the alkenyl bromides 18b and 23.

Tetramethylammonium pentacarbonyl(1-oxidoalkylidene)chromium(0) complexes, prepared from the corresponding carbanion and hexacarbonylchromium(0), are oxidized with manganese(III) 2-pyridinecarboxylate to generate carbon-centered radicals which react with various olefins giving the intermolecular addition products.

Enolate anions 3 and 6, prepared via enolization of α-bromo and dibromo ketones 4 and 5 were converted in high yield to ynolate anions 10 by respective addition of lithium tetramethylpiperidide (to effect deprotonation, 3 --> 7) or butyllithium (to effect metal-halogen exchange, 6 --> 7).Mixtures of such enolates were also obtainable from esters 1 on a large-scale (25 mmol) via in situ formation and addition of lithiodibromomethane (from methylene bromide and lithium tetramethylpiperidide), followed by treatment of the resulting adducts with lithiumhexamethyldisilazide to ensure complete enolization.Addition of sec-butyllithium and n-butyllithium to effect ynolate anion formation, followed by quenching of the reaction mixtures into acidic ethanol, reproducibly afforded homologated esters 8 in 67-90percent yield.Demonstrated for ethyl esters 1 having the carbethoxy moiety attached to primary, secondary, tertiary, aryl, and alkenyl groups, this general procedure provides a convenient, large-scale alternative to the classical Arndt-Eistert sequence.

The stereodynamics in l,4-dimethoxy-2,3,5,6-tetraethylbenzene (5), 1,4-bis(metboxymethyl)-2,3,5,6-tetracthylbenzene (6), and l,4-dineohexyl-2,3,5,6-tetraethylbenzene (7) and their respective tricarbonylchromium complexes, 5(Cr), 6(Cr), and 7(Cr), have bee

A general method has been developed for the overall transformation of α-bromo ketones to α-alkyl or α-aryl ketones, with benzotriazole being used as a synthetic auxiliary, α-Benzotriazolyl ketones, when converted into their phenylhydrazones, reacted smoothly with alkyl and aryl Grignard reagents, which displaced benzotrazolate, to give the corresponding α-alkyl and α-aryl hydrazones.In some cases, these hydrolysed directly to the α-alkyl or α-aryl ketones.In each case, the product was treated with 2,4-dinitrophenylhydrazine to isolate the target ketones as the corresponding 2,4-dinitrophenylhydrazones.

An electrochemical process for effecting directed aldol condensation is described.It is carried out under neutral conditions, can tolerate a wide variety of functional groups, is highly selective for aldehydes over ketones, requires only simple apparatus, and depends for its success upon the efficient mediating effect of trivalent lanthanide ions.

The SRNl free radical chain reaction of Me3CHgCl with nitronate -O2N=C(R1)(R2)> and phenone enolate -)=C(R1)(R2)> anions yields the C-alkylation products 1)(R2)NO2, PhCOC(R1)(R2)CMe3>.Competitive reactions between pairs of anions demonstrate that as the basicity of the anion increases the reactivity toward Me3Cat first increases and then decreases.An inverted reactivity order is also observed with phenylacetonitrile anions.In early transition state reactions, the nucleophilic character of the tert-butyl radical apparently controls the reactivity by virtue of a transition state involving transfer of the electron from radical to the LUMO of the resonance stabilized anion.

(α-Methoxybenzyl)trimethylsilane is deprotonated with butyllithium and then allowed to react with a variety of carbonyl compounds giving vinyl ethers which are convertible into methyl ketones under mild conditions.

The conformational equilibria and barriers to rotation in α-R-ββ-di-isopropylstyrenes with R=H, Me, Et, Pri, CH2But, and But, and in tri-isopropylethylene and 1,1,2-tri-isopropylpropene investigated by dynamic 1H n.m.r. spectroscopy and molecular mechanics (MM2, MMP2 force fields) are reported.The following conclusions are drawn: (i) the phenyl group is twisted ca. 70-90 degree out of the ethylene plane, (ii) the conformational populations of the geminal isopropyl groups indicate that the effective steric size of the phenyl group is larger than that of methyl, ethyl, isopropyl, and neopentyl groups, but smaller than that of the t-butyl group, (iii) barriers (ΔG(excit.)) to interchange of the isopropyl groups fall in the range 10.5-12.2 kcal mol-1, (iv) molecular mechanics calculations fail to reproduce the experimentally determined conformational populations but satisfactorily reproduce the barriers to rotation of the isopropyl and phenyl groups.According to these calculations the isopropyl group rotations are not correlated.

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Halodiorganoboranes R2BHal(R = Et, Ph) as well as benzyldihaloboranes PhCH2BHal2 undergo a regiospecific addition to the triple-bond of 1-alkynes ACCR'.The reversible haloboration (1) gives Z-alkenes as the more stable isomers.At elevated temperatures, the irreversible 1,1-organoboration (2) predominates, accompanied by a 1,2-transfer of A, whereas the 1,2-organoboration (3) is observed only as an unimportant side-reaction in a few cases.The cyclisation (4) occurs as a sequence of cis-haloboration and intramolecular aromatic alkenylation in the case of PhCH2BCl2 as borating agent.

The preparation of the α-haloketones 6, 13-16, 19, and 20 is reported. 13 or its precursor, the acyloin 9, respectively, is conveniently obtained by a Seebach synthesis. - Reaction of the haloketones with tetraethylammonium thiosulfate (21) yields the Bunte salts 22-27 wich form the thioketones 28-33 on cleavage with aqueous alkali. 29 is stable as a crystalline, blue monomer in contrast with other aromatic α-thioxoketones.This ist also true for the aromatic-aliphatic derivatives 30 and 31 as well as their isomers 32 and 33 wich do not dimerize.

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