Amide Source Research Articles

Photoinduced Direct Carbamoylation of Ethers with Isocyanates towards the Synthesis of α-Amide-Substituted Ether Derivatives

AbstractPhotoinduced carbamoylation of ethers using isocyanates as amide sources was accomplished under mild and environmentally friendly reaction conditions. A series of isocyanates were tolerated in this protocol to construct α-amide-substituted ether derivatives with desired yields. The method featured broad substrate scope and good functional group tolerance, which could play an important role in the construction of biological molecules with ethers.

Electrochemical Approach to Amide Bond Formation

AbstractElectrochemical amidation of the C(sp2)−H and C(sp3)−H bonds of broad spectrum of arenes toward the direct synthesis of anilides and N‐benzylamides under mild conditions (room temperature, ambient pressure) in the absence of metal catalyst and external oxidizing agents using nitriles RCN (R=Me, Et) as amide source is described. This electrochemical approach features moderate to high yields, a broad scope of arenes with different functional groups and is amenable to gram scale synthesis. The key role of the hydroxyl radical as inductor generated during the oxidation of water and fixed by a spin trap in EPR experiment has been established.

Rh(III)-Catalyzed ortho-C-H Amidation of Naphthalene and Perylene Monoimides.

The direct formation of a C-N bond at the ortho-position of naphthalene monoimides (NMI) and perylene monoimides (PMI) is reported herein using dioxazolones as the amide source. This method affords direct access to ortho-amino NMI and PMI through an amidation and deprotection sequence. One-pot telescopic bay-bromination of ortho-amino PMIs was also achieved. The ortho-amidated NMIs and PMIs, accessed by the current methodology, show significant red shifts in their absorption and fluorescence spectra compared with the NMI and PMI alone. An improvement in the quantum yield and fluorescence lifetime was observed by the incorporation of pivalamide groups at the ortho-positions of NMI and PMI.

Mechanochemical Rhodium-Catalyzed C-H Bond Amidation of Ferrocenes by Ball Milling.

A direct protocol for Rh-catalyzed C-H amidation of ferrocenes in a ball mill using dioxazolones as the amide source under solvent-free conditions was developed. The corresponding ortho-aminated products were formed in 3 hours and the yields were up to 99% in the absence of base. This method could be a typically sustainable and environmental-friendly alternative method to traditional methodologies, with the advantages of wide substrate range, good functional group tolerance and gram-scale synthesis.

Reaction of Dioxazolones with Boronic Acids: Copper-Mediated Synthesis of N-Aryl Amides via N-Acyl Nitrenes.

Dioxazolones, as direct amide sources, have been used with boronic acids in the presence of copper(I) chloride to access N-aryl amides at room temperature. The versatility of the developed reaction is proven by ample scope having a wide range of functional group tolerance. The reaction optimization conditions revealed that a fluorine additive demonstrated improved reactivity toward the intended transformation. The addition of triphenylphosphine resulted in N-acyl iminophosphorane, suggesting the involvement of an N-acyl nitrene intermediate.

Rhodium-Catalyzed Azine-Directed C-H Amidation with N-Methoxyamides.

Using N-methoxyamide reagents as an amide source, C-H amidation was realized at the ortho position of azine under the action of rhodium and boric acid. The method has mild reaction conditions, high atomic utilization, excellent yield, and wide adaptability to amidation reagents (both aromatic amides and fatty amides are applicable). Amide-substituted ketones can be obtained by a simple treatment and can be further transformed into bioactive substances. This provides a good supplement for the C-H bond amidation of aromatic rings.

Phytochemistry and Pharmacology of the Genus Zanthoxylum (Rutaceae): A Review

Background: The genus Zanthoxylum (Rutaceae) represents an interesting source of bioactive compounds, and more than 220 accepted species of this genus are distributed in the warm temperate and subtropical regions of the world. Different plant parts of Zanthoxylum species have been used traditionally as medicines for various diseases affecting both humans and animals. Based on traditional knowledge, several phytochemical and pharmacological studies have been conducted. Objective: This review aims to provide up-to-date information about the phytochemistry and pharmacology of the genus Zanthoxylum, covering literature published from January 2012 to mid-2019. Methods: The traditional medicinal uses, phytochemical and pharmacological data about Zanthoxylum species were searched and obtained from scientific databases such as Google Scholar, PubMed, SciFinder and Web of Science. Information about the accepted number of Zanthoxylum species was obtained from the Global Biodiversity Information Facility and Plants of the World online databases. Results: The genus Zanthoxylum (Rutaceae) is a rich source of structurally diverse secondary metabolites with promising pharmacological activities. Approximately 126 new secondary metabolites, including alkaloids, amides, lignans and neolignans, coumarins, peptides, terpenoids, and flavonoids have been isolated and identified from different Zanthoxylum species. The numerous studies have shown that compounds isolated from the genus Zanthoxylum exhibit pharmacological activities, including anti-inflammatory, antimicrobial, cytotoxic, larvicidal, antioxidant, anticancer/ antiproliferative, and antimycobacterial activities. Conclusion: Zanthoxylum genus, a rich source of alkaloids, amides, lignans and neolignans, coumarins, peptides, terpenoids, and flavonoids, is an interesting genus with multiple pharmacological activities. This review summarises phytochemical and pharmacological studies conducted so far. The data collected from the available literature shows that plants of the genus Zanthoxylum have great pharmacological potential. However, the genus is not fully explored and many gaps in the knowledge still exist.

Efficient synthesis of β-nitro amides by aminocarbonylation of ethoxycarbonyl-containing nitroalkenes with carbamoylsilane

Direct aminocarbonylation of β-nitroalkenes bearing β-positioned ethoxycarbonyl group using carbamoylsilane as an amide source afforded β-nitro amide derivatives under mild conditions without use of catalysts.

Response of Dry Bean to Nitrogen Fertilization and Inoculation with Rhizobium Tropici and Azospirillum Brasiliensis

ABSTRACT The dry bean (Phaseolus vulgaris L.) has significant economic importance in Brazil and is one of the most important sources of income, especially for small producers. This study aimed to evaluate the response of dry bean to different nitrogen (N) sources, using a completely randomized design, with five replicates. Treatments comprised five N sources [ammonium sulfate [(NH4)2SO4], calcium nitrate [Ca(NO3)2], potassium nitrate (KNO3), ammonium nitrate (NH4NO3), and urea] applied at 300 mg kg−1 N plus three additional treatments (inoculation with Rhizobium tropici, inoculation with R. tropici plus Azospirillum brasiliensis, and the control without N and inoculation). The yield components [grain yield (GY), shoot dry weight yield (SDWY), number of pods per pot (NPP), number of grains per pot (NGPt), pod weight (PW), and number of grains per pod (NGP)], and physiological components [water use efficiency (WUE), photosynthetic rate (A), and stomatal conductance (gs)] were evaluated. Inoculation with R. tropici and R. tropici plus A. brasiliensis did not induce significant effects on yield components when compared to those of the control. (NH4)2SO4 did not change the performance of most quantified yield components, whereas NH4NO3 showed increases in GY, SDWY, NPP, NGP, and PW as well as in WUE. KNO3 and Ca(NO3)2 resulted in increased performance of GY, SDWY, NPP, A, and gs compared to that in the control treatment and the isolated inoculant and its combination with A. brasiliensis. The amide source via urea showed the greatest increase in GY, with 56.5% more than that in the control.

Efficient synthesis of α-amino secondary amides by direct aminocarbonylation of N-Boc-imines using carbamoylsilane as an amide source

A novel and practical procedure for the preparation of α-amino secondary amides by the aminocarbonylation of N-Boc-imines using carbamoylsilanes bearing methoxymethyl group as secondary amides source is presented herein. The protocol tolerates N-Boc-imines bearing different groups, including aryl, double bond conjugated aryl, heteroaryl and aliphatic groups. The reactions provide good to excellent yields of the products under mild and catalysts-free conditions. The electronic property and the steric hindrance of substituent on the N-Boc-imines affect the reaction.

Efficient Synthesis of β-Keto-α-hydroxy Secondary (Primary) Amides by Selective Aminocarbonylation of Vicinal Diketones Using Carbamoylsilane as an Amide Source

Efficient Synthesis of <i>β</i>-Keto-<i>α</i>-hydroxy Secondary (Primary) Amides by Selective Aminocarbonylation of Vicinal Diketones Using Carbamoylsilane as an Amide Source

Nickel‐catalyzed aminocarbonylation of aryl halides with carbamoylsilanes: efficient synthesis of secondary (primary) aromatic amides

A nickel‐catalyzed aminocarbonylation of aryl halides using carbamoylsilane as an amide source leading to corresponding secondary or primary aromatic amides has been developed, in which the methoxymethyl and benzyl were used as amino protecting group. The protocol tolerates a broad range of aryl halides bearing different functional groups to afford good yields of aryl amides under mild reaction conditions. The types and the relative positions of substituents on the aryl ring make a notable impact on the coupling efficiency. The plausible mechanism of nickel‐catalyzed aminocarbonylation has been suggested.

Characterising Particulate Organic Nitrogen at A Savannah-Grassland Region in South Africa

Although atmospheric organic N compounds are considered to be important, especially in new particle formation and their contribution to brown carbon, these species are not that well understood. This can be partially attributed to their chemical complexity. Therefore, the aim of this study was to assess the characteristics of organic N compounds utilising comprehensive two-dimensional gas chromatography coupled with a time-of-flight mass spectrometer (GCxGC-TOFMS) in aerosol samples that were collected at a savanna-grassland background region and to determine the possible sources. 135 atmospheric organic N compounds were tentatively characterised and semi-quantified, which included amines, nitriles, amides, urea, pyridine derivatives, amino acids, nitro-and nitroso compounds, imines, cyanates and isocyanates, and azo compounds. Amines contributed to 51% of the semi-quantified concentrations, while nitriles, pyridine derivatives, and amides comprised 20%, 11%, and 8%, respectively, of the semi-quantified concentrations. Amines, nitriles, amides, and pyridine derivatives concentrations were higher during the dry season, which were attributed to meteorology and open biomass burning. Anthropogenic sources impacting air masses measured at Welgegund, as well as regional agricultural activities, were considered as the major sources of amines, while the regional influence of household combustion was most likely the main source of nitriles, amides, and pyridine derivatives. The other organic N species were most likely related to the influence of local and regional agricultural activities.

Synthesis of 3-Hydroxy-3-heterocyclebutylamide Derivatives Using Carbamoylsilanes as an Amide Source

Synthesis of 3-Hydroxy-3-heterocyclebutylamide Derivatives Using Carbamoylsilanes as an Amide Source

Formulation and evaluation of mosquito repellent ointment prepared with the essential oil of Zanthoxylum acanthopodium DC. Indigenous to Northeast India

Background: Medicinal plants have sanitary properties due to the bearing of several complex chemical substances of different composition, which are found as secondary plant metabolites in one or more parts of the plants. The genus Zanthoxylum covered to have many useful orthodox uses including antifungal, hepatoprotective, antibacterial, cytotoxic, and antioxidant activity. This Zanthoxylum genus is a rich source of alkaloids, ligands, steroids, coumarins, benzenoids, terpenes, flavonoids, fatty acids, and amides. Zanthoxylum acanthopodium DC is an aromatic plant and has been reported as an excellent mosquito repellent. Aim: The determination of the study was to formulate and evaluate the mosquito repellent ointment from the essential oil of the fruits of Z. acanthopodium DC. Methods: The formulated ointment was subjected to evaluation of the compatibility of essential oil and ointment base, measurement of pH, viscosity, spreadability, extrudability, stability study, drug content of ointment, and especially mosquito repellent evaluation such as first larvicidal evaluation of oil then repellent evaluation of ointment against Aedes aegypti and Culex quinquefasciatus. Acute and subchronic dermal irritation studies were also done. Results and Discussion: Our analysis shows that Z. acanthopodium DC has high potential as a mosquito repellent agent when formulated as ointment for topical use. Thus, the study resolves that the formulated ointment formulations of the essential oil from the fruits of Z. acanthopodium were safe and effective carriers with potent mosquito repellent activity.

Metal‐free Deoxygenative 2‐Amidation of Quinoline N‐oxides with Nitriles via a Radical Activation Pathway

AbstractA metal‐, base‐ and reductant‐free approach for the efficient synthesis of various N‐acylated 2‐aminoquinolines was reported. In this work, readily available nitriles are used as the amide source, and methyl carbazate as both the radical activating reagent and oxygen source. This is the first report on the ester‐radical‐activated highly regioselective addition of nitriles to quinolone N‐oxides. This procedure is expected to complement the current methods for functionalization of N‐oxides via an electrophilic activation mechanism.magnified image

Synthesis of α-(N-Sulfonyl)amino Amides Derivatives Using Carbamoylsilanes as an Amide Source

Synthesis of <i>α</i>-(<i>N</i>-Sulfonyl)amino Amides Derivatives Using Carbamoylsilanes as an Amide Source

Palladium-catalyzed Aminocarbonylation of Benzylic Chlorides Using Carbamoylsilane as an Amide Source: Efficient Access of Secondary Aryl Acetamides

Aim and Objective: Amides are a very important class of organic compounds. As a type of important amides, arylacetamides have gained considerable attention since their pharmacological and biological activities. Therefore, the development of new methods for the synthesis of aryl acetamides is of significant interest among organic chemists. Material and Method: Using N-methoxymethyl-N-methylcarbamoyl(trimethyl)silane as a secondary amide source, the aminocarbonylation of benzylic chlorides by palladium-catalyzed afforded the corresponding protected secondary arylacetamides in good yields under mild reaction conditions. The methoxymethyl group was used as an amino protecting group and can be easily hydrolyzed in acid condition to afford secondary arylacetamides. Results: A novel and highly efficient synthetic method toward secondary arylacetamides by palladium– catalyzed aminocarbonylation of aryl halides was developed using N-methoxymethyl-N-methylcarbamoyl(trimethyl) silane as secondary arylacetamides source, and investigated the scope and limitation of the aminocarbonylation. The relative position of substituent on the aryl ring to influence on this transformation. In this protocol, the methoxymethyl group was used as an amino protecting group and can be easily hydrolyzed. Conclusion: We have investigated the scope and limitation of the aminocarbonylation of benzylic chlorides with carbamoylsilane, expanded to synthesis of secondary arylacetamides using N-methoxymethyl-Nmethylcarbamoyl( trimethyl)silane as a secondary amide source. Keywords: Benzylic chlorides, carbamoylsilane, amides, C–C Coupling, aminocarbonylation, arylacetamides.

Synthesis of Secondary Aromatic Amides via Pd-Catalyzed Aminocarbonylation of Aryl Halides Using Carbamoylsilane as an Amide Source.

Using N-methoxymethyl-N-organylcarbamoyl(trimethyl)silanes as secondary amides source, the direct transformation of aryl halides into the corresponding secondary aromatic amides via palladium-catalyzed aminocarbonylation is described. The reactions tolerated a broad range of functional groups on the aryl ring except big steric hindrance of substituent. The types and the relative position of substituents on the aryl ring impact the coupling efficiency.

Synthesis of aryl acetamides by aminocarbonylation of benzylic chlorides using carbamoylsilane as an amide source

ABSTRACTUsing N-methyl-N-(1-phenyl)ethylcarbamoyl(trimethyl)silane as an amide source, the direct transformation of benzylic chlorides into the corresponding aryl acetamides through palladium-catalyzed aminocarbonylation is described. The electronic property and the relative position of substituents on the aromatic ring impact the coupling efficiency.