Regioselectivity of Intramolecular Electrophilic Cyclization of 2-(Alkenylsulfanyl)thieno[2,3-d]pyrimidin-4(3H)-ones with p-Methoxyphenyltellurium Trichloride

Kut, M. M.; Onysko, M. Yu.; Suikov, S. Yu.; Lendel, V. G.

doi:10.1134/s1070428020100061

Cited by 3 publications

(3 citation statements)

References 28 publications

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“…As results, the fused polycyclic pyrimido[2,1‐b][1,3]thiazinium salts 9‐16 were synthesized. In contrast to the halocyclization of terminally unsubstituted alkenyl (thio‐)ethers [20–26], the electrophilic cyclization of cinnamyl thioethers 5‐8 leads to the annulation of six‐membered thiazine ring. This phenomenon can be explained by the polarization of the double bond under the impact of the phenyl substituent and its steric impact, which leads to the formation of stable intermediate cations B1,B2 and further their cyclization into target salts 9‐16 (Scheme 3).…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, the halogens are convenient electrophilic reagents, which are widely used in heterocyclic chemistry [15–19]. In our previous work, we have established that electrophilic halogencyclization of terminally unsubstituted alkenyl (thio‐)ethers of fused heteroarylpyrimidinones results in the annulation of the thiazoline ring [20–26]. There are interesting features associated with the hindered rotation of aromatic substituent in the NMR spectra of condensed pyrazolothiazolopyrimidinium trihalides containing phenyl substituent at the heterocyclic nitrogen [22], which result to the chemical shifts of all the magnetic nuclei of the phenyl residue becoming anisochronous.…”

Section: Introductionmentioning

confidence: 99%

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Highly efficient synthesis and NMR features of novel fused pyrimidothiazinium trihalogenides

Onysko

Svalyavin

Slivka

et al. 2021

Journal of Heterocyclic Chem

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Condensed pyrimidines are a popular class of heterocyclic compounds because they have a wide range of biological activity. This article aims to evaluate the simple, catalyst‐free procedure of synthesis of novel fused pyrimidothiazines. An efficient access to a series of pyrazolo[4′,3′:5,6]pyrimido[2,1‐b][1,3]thiazinium, pyrazolo[3′,4′:5,6]pyrimido[2,1‐b][1,3]‐thiazinium, and benzo[b]thieno[4′,3′:5,6]pyrimido[2,1‐b][1,3]thiazinium trihalogenides was developed via electrophilic heterocyclization of corresponding pyrimidine cinnamyl thioethers under the action of halogens. The XDR and complex NMR investigations were used for solving of final products structure; the anisochronism was observed in the NMR spectra of synthesized compounds for the pairs of ortho‐ and meta‐protons, as well as the N‐phenyl substituents associated with them.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Highly efficient synthesis and NMR features of novel fused pyrimidothiazinium trihalogenides

Onysko

Svalyavin

Slivka

et al. 2021

Journal of Heterocyclic Chem

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“…In the study of the cyclization of 2‐(alkenylthio)thienopyrimidinones 61 by the action of electrophilic 4‐methoxyphenyltellurium trichloride, it has been found that N3‐unsubstituted substrate 61 (R 2 =H) undergoes an electrophilic attack on the N3 atom to afford telluro‐functionalized linear thiazolothienopyrimidinone 62 , whereas its 3‐phenyl analogue 61 (R=Ph) is cyclized at the N1 atom leading to the corresponding angular thiazolium salt 63 (Scheme 17). [100] …”

Section: Cyclizations Of 2‐alkenyl(alkynyl) Functionalized Quinazolin...mentioning

confidence: 99%

Cyclizations of Alkenyl(Alkynyl)‐Functionalized Quinazolinones and their Heteroanalogues: A Powerful Strategy for the Construction of Polyheterocyclic Structures

Vaskevych,

Dekhtyar,

Vovk

2023

The Chemical Record

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Quinazolin‐4‐one, its heteroanalogues, and derivatives represent an outstandingly important class of compounds in modern organic, medicinal, and pharmaceutical chemistry, as these molecular structures are noted for their wide synthetic and pharmacological potential. In the last years, ever‐increasing research attention has been paid to quinazolinone derivatives bearing alkenyl and alkynyl substituents on the pyrimidinone nucleus. The original structural combination of synthetically powerful endocyclic amidine (or amidine‐related) and exocyclic unsaturated moieties provides a driving force for cyclizations, which offer an efficient toolkit to construct a variety of fused pyrimidine systems with saturated N‐ and N,S‐heterocycles. In this connection, the present review article is mainly aimed at systematic coverage of the progress in using alkenyl(alkynyl)quinazolinones and their heteroanalogues as convenient bifunctional substrates for regioselective annulation of small‐ and medium‐sized heterocyclic nuclei. Much attention is paid to elucidating the structural and electronic effects of reagents on the regio‐ and stereoselectivity of the cyclizations as well as to clarifying the relevant reaction mechanisms.

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Synthesis and Some Transformations of 4-Oxo-7-phenyl-3,4,5,6,7,8-hexahydro[1]benzothieno[2,3-d]pyrimidine-7-carbonitrile

et al. 2021

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Regioselectivity of Intramolecular Electrophilic Cyclization of 2-(Alkenylsulfanyl)thieno[2,3-d]pyrimidin-4(3H)-ones with p-Methoxyphenyltellurium Trichloride

Cited by 3 publications

References 28 publications

Highly efficient synthesis and NMR features of novel fused pyrimidothiazinium trihalogenides

Highly efficient synthesis and NMR features of novel fused pyrimidothiazinium trihalogenides

Cyclizations of Alkenyl(Alkynyl)‐Functionalized Quinazolinones and their Heteroanalogues: A Powerful Strategy for the Construction of Polyheterocyclic Structures

Synthesis and Some Transformations of 4-Oxo-7-phenyl-3,4,5,6,7,8-hexahydro[1]benzothieno[2,3-d]pyrimidine-7-carbonitrile

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