Methanolysis of amides under high-temperature and high-pressure conditions with a continuous tubular reactor

The methanolysis of amides,which is widely employed in the synthetic organic chemistry,hardly occurs under mild conditions.To safely and controllably intensify the methanolysis reaction with hightemperature and high-pressure environment,a continuous tubular reaction technology is developed,whose space-time yield is over twice of that of the conventional batch reaction.The methanolysis of acetanilide is selected as the representative reaction,and the influences of temperature,pressure,reactant and catalyst concentration,and residence time on the reaction performances are systematically investigated.Taking the advantages of precise temperature and reaction time control by the tubular reactor,the kinetics of acetanilide methanolysis are determined and compared to the kinetics of acetanilide hydrolysis reaction.The tubular reaction method is also employed to test a variety of other amides to show the effects of substituents,steric hindrance,and alkalinity on the reaction rate of methanolysis.

The Anticancer Activities Phenolic Amides from the Stem of Lycium barbarum

Four new phenolic amides,4-O-methylgrossamide(1),(E)-2-(4,5-dihydroxy-2-{3-[(4-hydrox-yphenethyl)amino]-3-oxopropyl}-phenyl)-3-(4-hydroxy-3-methoxyphenyl)-N-(4-hydroxyphenethyl)acryl-amide(2),(Z)-lyciumamide C(3),(Z)-thoreliamide B(4),together with thirteen known phenolic amides were identified from the stem of Lycium barbarum.The structures of the new compounds were determined by spectroscopic methods.All compounds were evaluated for their anti-cancer activities against human glioma stem cell lines.

Amides,Isoquinoline Alkaloids and Dipeptides from the Aerial Parts of Piper mullesua

One undescribedamide,pipermullesine A,twoundescribed isoquinoline alkaloids,pipermullesinesBand C,and six undescribed dipeptides,pipermullamides A–F,along with 28 known compounds,were isolated from the aerial parts of Piper mullesua.The structures of the undescribed compounds were elucidated based on the analysis of 1D and 2D NMR and MS data.Furthermore,the structures of pipermullesines A–Cwere confirmed by single crystal X-ray diffraction analysis.All isolates were evaluated for inhibitory activity against platelet aggregation induced by thrombin(IIa)or platelet-activating factor(PAF).(-)-Mangochinine,pellitorine,and(2E,4E)-N-isobutyl-2,4-dodecadienamide showed weak inhibitory activity against rabbit platelet aggregation induced by PAF,with IC_(50)values of 470.3μg/mL,614.9μg/mL,and 579.7μg/mL,respectively.

Highly-Efficient Conversion of Primary Amides to Nitriles Using Indium(III) Triflate as the Catalyst

Indium(III) triflate, a trivalent indium reagent, was shown to be a highly-efficient catalyst for the conversion of primary amides to the corresponding nitriles. The successful reactions required 5 mol% of indium(III) triflate, and toluene was proved to be the most suitable solvent. Various amides were subjected to this method, and each produced the corresponding nitriles in excellent yields.

Selective Reduction of α,β-Unsaturated Amides with NaBH_4/BiCl_3 System

?β-Unsaturated amides with various substitution pattems at the carbon-carbon double And and nitrogen atom can be reduced to the corresponding saturated amides with high selectivity and yields with NaBH4/BiCl3 system.

The Synthesis of Tertiary Amides by theReaction of Adducts of Schiff Bases andAcyl Chlorides with Allylsamarium Bromide

Adducts of Schiff bases and acyl chlorides react with allylsamarium bromide to afford the corresponding tertiary amides.

New Amides and Phenylpropanoid Glucosides from the Fruits of Piper retrofractum

Two new amides(E)-N-cinnamoyl-2-methoxypiperidine(1)and(R)-1-(2-oxopyrrolidin-3-yl)-5,6-dihydropyridin-2(1H)-one(2),four new amide glucosides,retrofractosides A-D(3-6),and two new phenylpropanoid glucosides,retrofractosides E(7)and F(8),together with 24 known compounds(9-32)were isolated from the fruits of Piper retrofractum.The chemical structures of these new compounds were elucidated based on extensive spectroscopic analysis.All of these isolates(1-32)were evaluated for inhibitory activity against mouse platelet aggregation induced by the peptide AYPGKF-NH2.(E)-N-(Tetrahydro-2H-pyran-2-yl)cinnamamide(9)showed a weak inhibitory efect,with an inhibition ratio of 52.0%at a concentration of 150μM.

Synthesis, Characterization and Properties of Poly(aryl amides) Containing Methoxy Substituted Phthalazinone Moiety

A novel aromatic diamine, 1, 2-dihydro-2-（4-aminophenyl）-4-[3-methoxy-4-（4-aminophenoxy）]-2, 3-phthalazin-l-one （OO-DA） containing aza heterocyclic structure was synthesized from the bisphenol-like monomer in two steps and used for preparing new aromatic polyamides with high inherent viscosity of 0.89-1.03 dL.g^-1. The structures of diamine and polymers obtained were confirmed by MS, PT-IR, WAXD and ^1H-NMR. The synthesized polymers exhibited high glass transition temperature in the range of 281-307℃ and good solubility in polar solvents.

Synthesis of （2E）－α，β－Unsaturated Amides Catalyzed by Micro Palladium Under Solid－Liquid Phase－Transfer Conditions

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A FACILE SYNTHESIS OF 2-AND 2,4-UNSATURATED AMIDES

A convenient method for preparing unsaturated amides via telluro- nium salts employing solid potassium carbonate as a base with high stereo- selectivity in excellent yields has been developed.

Zirconium-hydride-catalyzed site-selective hydroboration of amides for the synthesis of amines:Mechanism,scope,and application

Developing mild and efficient catalytic methods for the selective synthesis of amines is a longstanding research objective.In this respect,catalytic deoxygenative amide reduction has proven to be promising but challenging,as this approach necessitates selective C-O bond cleavage.Herein,we report the selective hydroboration of primary,secondary,and tertiary amides at room temperature catalyzed by an earth-abundant-metal catalyst,Zr-H,for accessing diverse amines.Various readily reducible functional groups,such as esters,alkynes,and alkenes,were well tolerated.Furthermore,the methodology was extended to the synthesis of bio-and drug-derived amines.Detailed mechanistic studies revealed a reaction pathway entailing aldehyde and amido complex formation via an unusual C-N bond cleavage-reformation process,followed by C-O bond cleavage.

Cu-Pd Dual Catalyst System for Amide Styrylation Reaction from Potassium Styryltrifluoroborates and Amides

An interesting reaction procedure for the cross-coupling of potassium styryltrifluoroborates and amides has been developed by using PdCl2(dtbpf)-CuI dual catalyst system. By applying this method, good numbers of amide styrylation products are formed in 85% - 92% yields.

Facile Synthesis of Nitriles and Amides from Aldehyde over Heterogeneous Reusable Copper Fluorapatite (CuFAP) Catalyst under Neat Reaction Condition

A new robust heterogeneous, versatile, an environmentally benign, eco-friendly, recyclable CuFAP catalyst has been developed for the direct synthesis of nitriles and amides from aldehydes at 100°C for 6 h and 4 h, respectively, under neat reaction condition using hydroxylamine hydrochloride in the presence and the absence of tosyl chloride, respectively. Also the recyclability of catalyst as well as influence of solvents, additives on catalysts performance was investigated. The protocol can be considered as an alternative to conventional method for the synthesis of nitriles and amides in good to excellent yields. A highlight of our protocol is the easy separation of catalyst from reaction mixture, hence the catalyst is reused several times without significant loss of its catalytic activity.

Cobalt-Catalyzed Switchable[4+1]and[4+1+1]Spirocyclization of Aromatic Amides with 2-Diazo-1H-indene-1,3(2H)-dione:Access to Spiro Indene-2,1'-isoindolinones and Spiro Isochroman-3,1'-isoindolinones

Herein,we report a condition-controlled divergent synthesis of spiro indene-2,1'-isoindolinones and spiro isochroman-3,1'-isoindolinones through cobalt-catalyzed formal[4+1]and[4+1+1]spirocyclization of aromatic amides with 2-diazo-1H-indene-1,3(2H)-dione.When the reaction is carried out under air in ethyl acetate,spiro indene-2,1'-isoindolinones are formed through Co(II)-catalyzed C—H/N—H[4+1]spirocyclization.When the reaction is run under O2 in CH3CN,on the other hand,spiro isochroman-3,1'-isoindolinones are generated through Baeyer-Villiger oxidation of the in situ formed spiro indene-2,1'-isoindolinones with O2 as a cheaper and environmental-friendly oxygen source.In general,these protocols have advantages such as using non-precious and earth-abundant metal catalyst,no extra additive,high efficiency and regioselectivity.A gram-scale synthesis and the removal of the directing group further highlight its utility.

Copper-catalyzed conjugate addition of allene-derived nucleophiles to alkenyl-substituted carboxamides

Catalytic Michael addition reaction represents a fundamental importance in organic synthetic chemistry.Whereas corresponding conversions toward intrinsically low reactive enamide remains an ongoing challenging.We herein report a copper-catalyzed conjugate addition of allenes toβ-substituted alkenyl amides,one of the most challenging Michael acceptors.The present method utilizes readily available allenes as the latent carbon-based nucleophiles and simple,commonβ-substituted alkenyl amides as starting materials,unlike previous methods that usually preinstall an activating group to improve the reactivity of amide or uses highly reactive stoichiometric quantities of organometallics.Hence,this approach shows good functional group compatibility and can be implemented under mild reaction conditions with excellent level of chemo-and regioselectivities.

Divergent Synthesis of Primary Amides via Modular Dearomative Carbamoylations of Areneπ-Systems

In sharp contrast to the well researched and well developed aminocarbonylation of alkenes,the dearomative carbamoylation of abundant areneπ-systems has scarcely been studied despite its great potential to enrich the diversity-oriented synthesis of high-value amides.The formidable challenges associated with such dearomatization include the low reactivity of stable aromaticπ-systems and intricate selectivity issues.Herein,we disclose a general approach toward highly selective dearomative carbamoylations of areneπ-bonds under CO-gas-free conditions.Its extraordinary versatility was demonstrated by tolerating a broad range of nucleophilic partners with high yields and excellent selectivities,thus providing modular access to the divergent synthesis ofβ-functionalized primary amides.In addition,diverse downstream derivatizations including a formal C–H 1,2-olefination/carbamoylation reaction were conducted,exhibiting great potential in synthetic and medicinal chemistry.

Palladium-catalyzed 3,4-hydroaminocarbonylation of conjugated dienes for formation ofβ,γ-unsaturated amides

Hydrocarbonylation of conjugated dienes is one of the most promising yet challenging methods for the synthesis of carbonyl compounds.Herein,we reported the development of an unprecedented palladium-catalyzed branched selective 3,4-hydroaminocarbonylation of 1,3-dienes with CO and amines hydrochloride to affordβ,γ-unsaturated amides.This reaction employs readily available starting materials(including anilines,amines,amino acids,peptides,aryl-1,3-dienes,alyl-1,3-dienes)and tolerates a wide range of functional groups,thus providing a facile and effective approach to access a diverse array ofα-substitutedβ,γ-unsaturated amides.Mechanistic investigations suggested that the hydropalladation of dienes is irreversible,and the insertion of CO into the allyl-Pd species is probably the rate-limiting step.

Two new phenolic amides from Allium chinense

Objective: To isolate the phenolic amides from the dried bulbs of Allium chinense and investigate their myocardium protective activities.Methods: The chemical constituents were isolated and purified by combining with silica gel column,Sephadex LH-20 column, HPLC and other chromatography techniques. Their structures were elucidated by NMR techniques and mass spectrometry. The isolated compounds were evaluated to determine their protective effect for myocardium cells in vitro.Results: Two new phenolic amides, namely, alichinemide Ⅰ(1) and alichinemide Ⅱ(2), and six konwn amides were isolated from the dried bulbs of A. chinense. The structures of compounds 3–8 were identified as 3-indolcarbaldehyde(3), 1-(2-aminophenyl)urea(4), 2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylic acid(5), N-trans-feruloyltyramine(6), N-trans-p-coumaroyltyramine(7), and N-(3,4-dimethoxyphenethyl) acetamide(8). Compound 3(50 μmol/L) showed significant inhibitory effect on the damage of H9c2 myocardial cells induced by H2O2in vitro.Conclusion: Compounds 1 and 2 were new phenolic amides. Compound 3 could be one of the potential myocardium protective constituents of A. chinense.

Iridium and B(C_(6)F_(5))_(3) co-catalyzed chemoselective deoxygenative reduction of tertiary amides:application to the efficient synthesis and late-stage modification of pharmaceuticals

The Vaska’s complex—tris(pentafluorophenyl)borane combination was found to be a highly efficient cooperative catalysis system for the hydrosilylative reduction of tertiary amides to yield amines under mild conditions.The reaction shows high chemoselectivity,tolerating halide,phenolyl,alkenyl,nitro,nitrile,ester,azido,ketone,and enone functional groups.For unsubstituted cyclohexanone carboxamide,two variations were established to achieve either catalytic concomitant reduction of the two carbonyl groups or selective reduction of the amide carbonyl.The protocol was applied to the efficient synthesis and latestage modification of several pharmaceuticals and derivatives.Importantly,we showed that by simply prolonging reaction time to 24–28 h,the reaction can reach an exceptionally high efficiency with turnover number(TON)up to 9.8×10^(6) and turnover frequency(TOF)up to 408,333 at a quite low catalyst loading of 0.00001 mol%(S/C(Ir)=10,000,000).

Lanthanide-oxo clusters for efficient catalytic reduction of carboxamides

The reduction of carboxamides into high value-added amines is a very interesting but great challenging topic.Herein we demonstrate that polynuclear lanthanide-oxo clusters Ln16(Ln=Eu and Gd)can be used as efficient catalyst to reduce primary and secondary carboxamides to amines with excellent yield of 71%-98%and broad substrates scope.The methodology can extend to the gram-scale synthesis of phenethylamine drug with 93%yield.Based on the isolation and characterization of catalytic intermediates,a catalytic mechanism involving multipath reaction is proposed.This work provides efficient lanthanide cluster catalysts for the reduction of carboxamides to amines.