Highly Efficient Microwave-assisted One-Pot Synthesis of Aromatic Nitriles from Aromatic Aldehydes

Russian Journal of Organic Chemistry - A highly efficient and environmentally benign protocol is described for the microwave-assisted one-pot synthesis of aromatic nitriles from aromatic aldehydes...     

A SiCl4-ZnCl2 induced general, mild and efficient one-pot, three-component synthesis of β-amido ketone libraries

A general, mild and efficient protocol for the synthesis of β-amido ketone libraries was achieved utilizing tetrachlorosilane and zinc chloride in dichloromethane at ambient temperature via a one-pot, three-component condensation of various aldehydes, ketones and nitriles.     

A multicomponent synthesis of triazinane diones

An efficient, one-pot synthetic protocol toward triazinane diones, a rather unexplored class of heterocyclic scaffolds combining phosphonates, nitriles, aldehydes, and isocyanates is described. The optimization of the reaction, synthesis of a small library of different triazinane diones, as well as alternative routes toward the triazinane dione scaffold are discussed.     

Trifluoroethanol as a metal-free, homogeneous and recyclable medium for the efficient one-pot synthesis of α-amino nitriles and α-amino phosphonates

Trifluoroethanol is found to be an efficient and recyclable medium in promoting one-pot, three-component coupling reactions of aldehydes or ketones, amines and trimethylsilyl cyanide or trimethyl phosphite to afford the corresponding α-amino nitriles or α-amino phosphonates in high yields. This protocol does not require the use of an acid or base catalyst.     

Efficient synthesis of β-acetamido ketones using BF3/Et2O: a fertile approach toward avoiding usage of acetyl chloride

Abstract

A simple and efficient one pot synthesis of β-acetamido ketones from reaction of aldehydes, enolizable ketones, alkyl/aryl nitriles, and BF₃/Et₂O catalyst under microwave irradiations is described. This method allows synthesis of β-acetamido ketones without using corrosive and hazardous acetyl chloride. It is applicable for diversified aldehydes and active methylene ketones supported by synthesizing varieties of β-acetamido ketones. As per literature, majority of synthetic methods of β-acetamido ketones are restricted to use of acetonitrile lonely, as a nitrile component. This method is found to be equally effective for range of nitriles, also. Key features of reported method are simple reaction protocol, better yields, shorter reaction time, and nonhazardous reaction conditions which support the “Green Chemistry approach.”     

Oxoammonium salt-mediated oxidative nitriles synthesis from aldehydes with ammonium acetate

An efficient and scalable route for the synthesis of nitriles was developed by oxoammonium salt (4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate) mediated oxidative conversion of aldehydes with NH₄OAc. A variety of aliphatic aldehydes as well as benzaldehydes were converted into the corresponding nitriles in high yields. The nitroxyl radical which is the reduced species of the used oxoammonium salt was recovered by simple acid-base extraction for the recycling.     

Acetohydroxamic acid: a new reagent for efficient synthesis of nitriles directly from aldehydes using Bi(OTf)3 as the catalyst

An efficient method for the preparation of nitriles directly from aldehydes by reaction with AHA using Bi(OTf)₃ as the catalyst is described. Bi(OTf)₃ is shown to be an efficient catalyst also for the conversion of aldoximes into nitriles.     

Metalated nitriles: organolithium, -magnesium, and -copper exchange of alpha-halonitriles

[reaction: see text] alpha-Halonitriles react with alkyllithium, organomagnesium, and lithium dimethylcuprate reagents generating reactive, metalated nitriles. The rapid halogen-metal exchange with alkyllithium and Grignard reagents allows selective exchange in the presence of reactive carbonyl electrophiles, including aldehydes, providing a high-yielding alkylation protocol. Lithiated and magnesiated nitriles react with propargyl bromide by S(N)2 displacement whereas organocopper nitriles react by S(N)2' displacement, correlating with the formation of a C-metalated nitrile.     

Silica sulfuric acid/ethylene glycol as an efficient catalyst for the synthesis of benzo[4,5]imidazo[1,2-a]pyrimidine-3-carbonitrile derivatives

A simple and efficient eco-friendly method was developed for the synthesis of new benzo[4,5]imidazo[1,2-a]pyrimidine-3-carbonitrile derivatives in excellent yields. The synthesis was achieved through the reaction of 2-aminobenzimidazole, aldehydes and active nitriles (malononitrle or ethyl cyanoacetae) in the presence of silica sulfuric acid/ethylene glycol. This protocol offers very short reaction times (in some cases, reaction times were reduced to five minutes), high yields and low cost. This method thus provides an improvement over the existing methods.     

Copper(II)-catalyzed hydration of nitriles with the aid of acetaldoxime

An efficient method for the selective hydration of nitrile to amide by employing inexpensive copper salt catalyst and commercially available acetaldoxime in environmentally friendly water is described. Under this protocol, nitriles including aromatic nitriles, heterocyclic nitriles and aliphatic nitriles were converted into the corresponding amides in good to excellent yields.     

One-pot three-component synthesis of α-amino nitriles catalyzed by nano powder TiO_2 P 25

A simple and efficient method has been developed for the synthesis ofα-amino nitriles from aldehydes,amines and trimethylsilyl cyanide（Me₃SiCN） in the presence of a catalytic amount of cyanuric acid at room temperature.     

采用燃烧技术制备CuO纳米粒子:一种高效且环境友好的用于芳族醛合成芳族腈催化剂(英文)

CuO nanoparticles were synthesized using an energy-efficient and rapid solution combustion technique with malic acid employed as a fuel. The combustion-derived CuO nanoparticles were used as catalysts in a one-pot synthesis of aromatic nitriles from aromatic aldehydes and hydroxylamine hydrochloride. The catalyst was characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, transmission electron microscopy, and Brunauer-Emmett-Teller surface area analysis. The catalytic activity of the CuO nanoparticles in the synthesis of aromatic nitriles from aromatic aldehydes was evaluated. The present protocol offers the advantages of a clean reaction, simple methodology, short reaction duration (1-2 min), and high yield (85%-98%). The catalytic activity of the CuO nanoparticles was found to be higher than that of bulk CuO powder under the same conditions. The catalyst can also be recovered and reused up to four times with no significant loss of catalytic activity. The present approach is inexpensive and is a convenient technique suitable for industrial production of CuO nanoparticles and nitriles.     

L'acide hydroxylamine-O-sulfonique,réactif de choix pour la conversion d'aldéhydes en nitriles

Hydroxylamine-O-sulfonic acid: a convenient reagent for the conversion of aldehydes into nitriles . Hydroxylamine-O-sulfonic acid (HAS) proved to be an excellent reagent for the conversion of aliphatic, aromatic and heteroatomic aldehydes into nitriles. There, aldehydes in the form of suspension in HAS water solution, react rapidely to give the corresponding nitriles in high yield. Only with formylpyridines could the intermediate oxime-O-sulfonic acids be isolated.     

O,O-Diethyl dithiophosphoric acid mediated direct synthesis of thioamides from aldehydes and ketones

A general and convenient method for a one-pot conversion of aldehydes and ketones into thioamides has been developed. The protocol involves oximation of aldehydes and ketones followed by deoxygenative thioamidation of oximes with O,O-diethyl dithiophosphoric acid which acts as an acid as well a source of sulfur. The method is operationally simple, high yielding, and also applicable to the conversion of amides and nitriles into the corresponding thioamides.     

UV-Promoted Metal- and Photocatalyst-Free Direct Conversion of Aromatic Aldehydes to Nitriles

Russian Journal of Organic Chemistry - An efficient, simple, and catalyst-free UV-induced functional group transformation of aromatic aldehydes to nitriles has been reported. The developed strategy...     

Electric Field Enhanced Ammoxidation of Aldehydes Using Supported Fe Clusters Under Ambient Oxygen Pressure

Heterogeneous catalytic ammoxidation provides an eco-friendly route for the cyanide-free synthesis of nitrile compounds, which are important precursors for synthetic chemistry and pharmaceutical applications. However, in general such a process requires high pressures of molecular oxygen at elevated temperatures to accelerate the oxygen reduction and imine dehydrogenation steps, which is highly risky in practical applications. Here, we report an electric field enhanced ammoxidation system using a supported Fe clusters catalyst (Fe/NC), which enables efficient synthesis of nitriles from the corresponding aldehydes under ambient air pressure at room temperature (RT). A synergistic effect between the external electric field and the Fe/NC catalyst promotes the ammonia activation and the dehydrogenation of the generated imine intermediates and avoids the unwanted backwards reaction to aldehydes. This electric field enhanced ammoxidation system presents high efficiency and selectivity for the conversion of a series of aldehydes under mild conditions with high durability, rendering it an attractive process for the green synthesis of nitriles with fragile functional groups.     

Efficient Synthesis of β‐Alkyl/Arylsulfanyl Carbonyl Compounds by In‐TMSCl‐Promoted Cleavage of Dialkyl/Diaryl Disulfides and Subsequent Michael Addition

A convenient and efficient procedure for the synthesis of β‐alkyl/arylsulfanyl carbonyl compounds has been developed by a simple one‐pot reaction of dialkyl/diaryl sulfides with α,β‐unsaturated aldehydes, ketones, carboxylic esters, and nitriles in presence of indium and trimethylsilyl chloride under sonication.     

Highly efficient and convenient Strecker reaction of carbonyl compounds and amines with TMSCN catalyzed by MCM-41 anchored sulfonic acid as a recoverable catalyst

MCM-41 anchored sulfonic acid (MCM-41–SO₃H) was found to be a highly efficient and recoverable heterogeneous catalyst for the three-component Strecker reaction of aldehydes or ketones and diverse amines using trimethylsilyl cyanide (TMSCN) to afford the corresponding α-amino nitriles under mild conditions in high to quantitative yields. The simple experimental procedure along with easy recovery and reusability of the catalyst has led to development of a clean and environmentally friendly approach for the synthesis of α-amino nitriles.     

Exploring the versatility of the Johnson-Claisen rearrangement: access to functionally versatile δ-ethoxycarbonyl-α,β-unsaturated nitriles

A practical entry into δ-ethoxycarbonyl-α,β-unsaturated nitriles is described. α,β-Unsaturated aldehydes were converted to cyanohydrins, by employing either KCN in aqueous acid, or by using TMSCN with catalytic K₂CO₃, followed by acid hydrolysis of the TMS ether. These cyanohydrins underwent a Claisen rearrangement employing a modified Johnson-Claisen protocol to yield unsaturated nitriles in good yields and with moderate E/Z selectivity.     

One‐Pot Three‐Component Synthesis of α‐Amino Nitriles Catalyzed by 2,4,6‐Trichloro‐1,3,5‐triazine (Cyanuric Acid)

A simple and efficient method has been developed for the synthesis of α‐amino nitriles from aldehydes, amines and trimethylsilyl cyanide (Me₃SiCN) in the presence of a catalytic amount of cyanuric acid at room temperature.