synthetic intermediate
Recently Published Documents


TOTAL DOCUMENTS

247
(FIVE YEARS 25)

H-INDEX

22
(FIVE YEARS 2)

2021 ◽  
Vol 6 (2) ◽  
pp. 46-57
Author(s):  
Stanislav Fedorovich Merkushov

The author turns to the synthetic (intermediate) analysis of the musical composition Harvest by Denis Tretyakov. Two interpretative and semantic layers of the song text are identified and analyzed. The socio-historical (external) level of the text is realized through a decipherable event-plot code. The second (internal) level of the text is much more implicit, since it correlates with its metaphysical semiotic component. It is here that the key to an adequate interpretation is hidden. The song Harvest is connected with the ode To Joy (Beethoven / Schiller) both musically / melodically and textually. Moreover, the correlation of different levels can be traced with individual texts of other authors, in turn, conceptually correlated with this work. These are primarily Gnostic apocrypha (The Apocrypha of Johan, The Walk of the Virgin in Torment), the involvement of which serves to a certain extent the correct analysis of the central image (Misha Gorlikov). He can be identified with both Michael the archangel and the fallen angel Samael, which allows us to speak about the ambivalence not only of the image itself, but also of the picture unfolded in the text, represented as a universal model of the world. There are at least two ways of receiving the ode To Joy by Denis Tretyakov: embodying the original idea and rethinking it. Both solutions receive voluminous, multi-valued implementations, although it is the second way (reinterpretation) that is obviously semantically representative and dynamic. Thanks to the original explication of the musical and verbal sides of the composition, a new author's concept is born, a new own text, at the same time understood as a kind of gesture of art / anti-art.


Synlett ◽  
2021 ◽  
Author(s):  
Xiang Wu

Asymmetric organocatalysis is emerging as an elegant tool for accelerating chemical reactions and creating specific types of molecules. Chiral Brønsted acid catalysis is an important area of organocatalysis. Recently we described a chiral Brønsted acid (N-triflyl phosphoramide) catalyzed intramolecular iminium ion cyclization reaction of 2-alkenylbenzaldimines for the synthesis of chiral 1-aminoindenes and tetracyclic 1-aminoindanes in good yields and high enantioselectivities. The obtained 1-aminoindene can be utilized as useful synthetic intermediate for synthesis of (S)-rasagiline, an effective drug for the symptomatic treatment of Parkinson's disease. And the obtained tetracyclic 1-aminoindanes are the skeleton of homoisoflavanoid natural products such as brazilin.


Author(s):  
Adam Ametovski ◽  
Elizabeth A. Cairns ◽  
Katharina Elisabeth Grafinger ◽  
Annelies Cannaert ◽  
Marie H. Deventer ◽  
...  

2021 ◽  
Vol 25 (9) ◽  
pp. 15-21
Author(s):  
P. Sanjeeva ◽  
B. Subba Rao ◽  
V. Kamala Prasad ◽  
P. Venkata Ramana

The six benzofuran-oxadiazole derivatives (4a-d) and (5a-b) have been designed, synthesized, characterized and evaluated for antimicrobial activity. The key synthetic intermediate 5-bromo-N'-hydroxybenzofuran -2-carboxamidine (3) was prepared from 5-bromobenzofuran-2-carboxylic acid (1) in two consecutive steps involving reaction with NaN3, in presence of TEA, Xtalfluor-E, PPh3 in dry DCM at 0oC followed by the treatment of resulting carbonitrile (2) with hydroxylamine hydrochloride in presence of sodium methoxide under reflux in aqueous ethanol. Reaction of carboxamidine (3) with different aryl esters in presence of K2CO3 under reflux conditions in toluene afforded 3-(5-bromobenzofuran-2-yl)-5-substituted phenyl-1,2,4-oxadiazoles (4a-d) while the refluxion of a solution of carboxamidine (3) in dichloromethane with chloro/bromo acetyl chloride in presence of TEA and a catalytic amount of HBTU furnished 3-(5-bromobenzofuran-2-yl)-5-(chloromethyl)-1,2,4-oxadia zole (5a) and 3-(5-bromobenzofuran-2-yl)-5-(bromomethyl)-1,2,4-oxadiazole (5b).


Reactions ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 175-208
Author(s):  
Alexander J. Nicholls ◽  
Ian R. Baxendale

The benzo[1,2,3]dithiazole is a unique heteroaromatic functionality whose conjugated profile instils some fascinating electronic properties. This has been historically recognized in the design and manufacture of organic dyes early last century. Although, with the benefit of increased diagnostic techniques and improved understanding, these structures are attracting greater attention in additional research settings, including applications as organic radicals and semiconductors. In addition, the benzodithiazole functionality has been shown to be a valuable synthetic intermediate in the preparation of a variety of other privileged aromatic and heteroaromatic targets, many of which are important APIs. In this review, the authors aim to critically analyse the potential applicability of these compounds to the fields of not only small-scale laboratory synthetic and medicinal chemistry but also commercial-scale processes and increasingly materials chemistry.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3047
Author(s):  
John B. Bauer ◽  
Fatima Diab ◽  
Cäcilia Maichle-Mössmer ◽  
Hartmut Schubert ◽  
Holger F. Bettinger

The Diels–Alder cycloaddition between bisdienes and bisdienophile incorporating the 7-oxa-bicyclo[2.2.1]heptane unit are well known to show high diastereoselectivity that can be exploited for the synthesis of molecular belts. The related bisdiene 5,6,7,8-tetramethylidene-2-bicyclo[2.2.2]octene is a valuable building block for the synthesis of photoprecursors for acenes, but it has not been employed for the synthesis of molecular belts. The present work investigates by computational means the Diels–Alder reaction between these bisdiene building blocks with syn-1,4,5,8-tetrahydro-1,4:5,8-diepoxyanthracene, which shows that the diastereoselectivity of the Diels–Alder reaction of the etheno-bridged bisdiene is lower than that of the epoxy-bridged bisdiene. The reaction of the etheno-bridged bisdiene and syn-1,4,5,8-tetrahydro-1,4:5,8-diepoxyanthracene in 2:1 ratio yields two diastereomers that differ in the orientation of the oxa and etheno bridges based on NMR and X-ray crystallography. The all-syn diastereomer can be transformed into a molecular belt by inter- and intramolecular Diels–Alder reactions with a bifunctional building block. The molecular belt could function as a synthetic intermediate en route to a [11]cyclacene photoprecursor.


Synthesis ◽  
2021 ◽  
Author(s):  
Duy H. Hua ◽  
Bernard Wiredu ◽  
Mahendra Thapa ◽  
Sheen Y. Hua ◽  
John Desper

AbstractA new octaphenyl[4.4]triphenylparacyclophanediene was readily synthesized in six steps from p-xylene via the installment of bromine atoms, replacement with a vinyl group, carbonylative coupling, intermolecular followed by intramolecular double Grubbs olefin metathesis, Knoevenagel condensation, and Diels–Alder cycloaddition. The belt-shaped structure and trans-stereochemistry of the alkene moieties of the octaphenyl[4.4]triphenylparacyclophane and a synthetic intermediate, 2,21-dioxo-11,30-diene[3.4.3.4]paracyclophane, were determined by X-ray crystallography. The synthetic methodology leading to octaphenyl[4.4]triphenylparacyclophane is applicable for the synthesis of substituted triphenylparacyclophanes and possibly their corresponding bis-hexabenzocoronenylparacyclophanes via a Scholl–Mullen oxidative aryl-aryl coupling reaction.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takashi Ishida ◽  
Haruna Yoshimura ◽  
Masatsugu Takekawa ◽  
Takumi Higaki ◽  
Takashi Ideue ◽  
...  

AbstractThe discovery and useful application of natural products can help improve human life. Chemicals that inhibit plant growth are broadly utilized as herbicides to control weeds. As various types of herbicides are required, the identification of compounds with novel modes of action is desirable. In the present study, we discovered a novelN-alkoxypyrrole compound, kumamonamide fromStreptomyces werraensisMK493-CF1 and established a total synthesis procedure. Resulted in the bioactivity assays, we found that kumamonamic acid, a synthetic intermediate of kumamonamide, is a potential plant growth inhibitor. Further, we developed various derivatives of kumamonamic acid, including a kumamonamic acid nonyloxy derivative (KAND), which displayed high herbicidal activity without adverse effects on HeLa cell growth. We also detected that kumamonamic acid derivatives disturb plant microtubules; and additionally, that KAND affected actin filaments and induced cell death. These multifaceted effects differ from those of known microtubule inhibitors, suggesting a novel mode of action of kumamonamic acid, which represents an important lead for the development of new herbicides.


Molbank ◽  
10.3390/m1196 ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. M1196
Author(s):  
Diana Becerra ◽  
Hugo Rojas ◽  
Juan-Carlos Castillo

We reported an efficient one-pot two-step synthesis of 3-(tert-butyl)-N-(4-methoxybenzyl)-1-methyl-1H-pyrazol-5-amine 3 in good yield by a solvent-free condensation/reduction reaction sequence starting from 3-(tert-butyl)-1-methyl-1H-pyrazol-5-amine 1 and p-methoxybenzaldehyde 2. The one-pot reductive amination proceeded by the formation in situ of the N-(5-pyrazolyl)imine 4 as key synthetic intermediate of other valuable pyrazole derivatives. This methodology is distinguished by its operational easiness, short reaction time, isolation and purification of the aldimine intermediate is not required. The structure of the synthesized N-heterocyclic amine 3 was fully characterized by FTIR-ATR, 1D and 2D NMR experiments, EIMS, and elemental analysis.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cheng Zhang ◽  
Kemiao Hong ◽  
Chao Pei ◽  
Su Zhou ◽  
Wenhao Hu ◽  
...  

AbstractMetal carbene is an active synthetic intermediate, which has shown versatile applications in synthetic chemistry. Although a variety of catalytic methods have been disclosed for the generation of carbene species from different precursors, there is an increasing demand for the development of efficient and practical approaches for the in-situ formation of metal carbene intermediates with structural diversity and unrevealed reactivity. Herein we report a gold-catalyzed cascade protocol for the assembly of polycarbocyclic frameworks in high yields under mild reaction conditions. Mechanistic studies indicate that the unique β-aryl gold-carbene species, generated via gold-promoted 6-endo-dig diazo-yne cyclization, is the key intermediate in this reaction, followed by a [4 + 2]-cycloaddition with external alkenes. In comparison to the well-documented metal carbene cycloadditions, this carbene intermediate serves as a 4-C synthon in a cycloaddition reaction. A variety of elusive π-conjugated polycyclic hydrocarbons (CPHs) with multiple substituents are readily accessible from the initially generated products by a mild oxidation procedure.


Sign in / Sign up

Export Citation Format

Share Document