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Guo-qiang Lin - One of the best experts on this subject based on the ideXlab platform.
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Stereoselective synthesis of conjugated Trienes via 1,4-palladium migration/Heck sequence.
Chemical communications (Cambridge England), 2020Co-Authors: Ze-jian Xue, Bin-bin Zhu, Chen-guo Feng, Guo-qiang LinAbstract:Conjugated Trienes are ubiquitous structures in natural products and organic functional molecules. An efficient 1,4-palladium migration/Heck sequence was developed for the highly stereoselective synthesis of trisubstituent 1,3,5-Trienes, which were found to undergo easy E/Z isomerization in the presence of light.
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stereoselective synthesis of conjugated Trienes via 1 4 palladium migration heck sequence
Chemical Communications, 2020Co-Authors: Ze-jian Xue, Bin-bin Zhu, Chen-guo Feng, Guo-qiang LinAbstract:Conjugated Trienes are ubiquitous structures in natural products and organic functional molecules. An efficient 1,4-palladium migration/Heck sequence was developed for the highly stereoselective synthesis of trisubstituent 1,3,5-Trienes, which were found to undergo easy E/Z isomerization in the presence of light.
Chen-guo Feng - One of the best experts on this subject based on the ideXlab platform.
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Stereoselective synthesis of conjugated Trienes via 1,4-palladium migration/Heck sequence.
Chemical communications (Cambridge England), 2020Co-Authors: Ze-jian Xue, Bin-bin Zhu, Chen-guo Feng, Guo-qiang LinAbstract:Conjugated Trienes are ubiquitous structures in natural products and organic functional molecules. An efficient 1,4-palladium migration/Heck sequence was developed for the highly stereoselective synthesis of trisubstituent 1,3,5-Trienes, which were found to undergo easy E/Z isomerization in the presence of light.
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stereoselective synthesis of conjugated Trienes via 1 4 palladium migration heck sequence
Chemical Communications, 2020Co-Authors: Ze-jian Xue, Bin-bin Zhu, Chen-guo Feng, Guo-qiang LinAbstract:Conjugated Trienes are ubiquitous structures in natural products and organic functional molecules. An efficient 1,4-palladium migration/Heck sequence was developed for the highly stereoselective synthesis of trisubstituent 1,3,5-Trienes, which were found to undergo easy E/Z isomerization in the presence of light.
N. A. Nedolya - One of the best experts on this subject based on the ideXlab platform.
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structural reorganization of allyl benzyl and propargylsulfanyl substituted 2 aza 1 3 5 Trienes in t buok thf dmso access to rare functionalized 2 thiazolines
Tetrahedron Letters, 2014Co-Authors: N. A. Nedolya, O A Tarasova, A I Albanov, B A TrofimovAbstract:Abstract Treatment of (allyl-, benzyl-, and propargylsulfanyl)-substituted 2-aza-1,3,5-Trienes, which are readily accessible from lithiated methoxyallene, isopropyl isothiocyanate, and allyl, benzyl, or propargyl bromide, respectively, with t-BuOK in THF/DMSO resulted in the unexpected formation of 2-thiazoline derivatives along with seven-membered azaheterocycles [in the case of (allyl- and benzylsulfanyl)-substituted 2-aza-1,3,5-Trienes]. An unprecedented structural reorganization of the azaTrienes into 2-thiazolines presumably occurs via α-deprotonation of the substituents at the sulfur atom followed by intramolecular [1,5]-cyclization. Deprotonation of the ketimine fragment of the same molecule followed by [1,7]-electrocyclization resulted in azepine ring formation.
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simultaneous synthesis of 4 5 dihydro 3h azepines and 3h azepines bearing alkoxy and alkylsulfanyl substituents through metallation of 2 aza 1 3 5 Trienes by t buok
Journal of Organometallic Chemistry, 2011Co-Authors: N. A. Nedolya, Ol'ga G. Volostnykh, O A Tarasova, A I Albanov, B A TrofimovAbstract:Abstract A new range of alkoxy- and alkylsulfanyl-substituted 4,5-dihydro-3 H -azepines and 3 H -azepines have simultaneously been obtained from conjugated 2-aza-1,3,5-Trienes by treatment with t -BuOK under mild reaction conditions (THF/DMSO, ∼−30 °C, 30 min). One-pot synthesis of 1-aza-1,3,4-Trienes from α-lithiated alkoxyallenes, isopropyl isothiocyanate and alkyl iodides, followed by the thermally induced sigmatropic [1,5]-H shift, easily leads to starting 2-aza-1,3,5-Trienes. The reaction proceeds via generation and [1,7]-electrocyclization of azatrienyl anions and represents a novel simple approach to both azacycloheptadienes and azacycloheptaTrienes.
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Reactions of heterocumulenes with organometallic reagents: XVII. One-pot synthesis of alkoxy and (alkylsulfanyl)-substituted pyrroles and 2,3-dihydropyridines from aliphatic isothiocyanates and lithiated alkoxyallenes
Russian Journal of Organic Chemistry, 2011Co-Authors: N. A. Nedolya, O A Tarasova, A I Albanov, L. Brandsma, B A TrofimovAbstract:A fundamentally new approach was developed to designing pyrrole and dihydropyridine rings from available allenes and isothiocyanates involving a single preparative stage. Applying the reaction of lithiated alkoxyallenes with aliphatic isothiocyanates we have synthesized previously unknown 1-alkyl(cycloalkyl) pyrroles and 2,3-dihydropyridines with rare alkoxy- and alkylsulfanyl substituents. It was proved that the five- and six-membered azaheterocycles formed as a result of competing reactions of direct intramolecular cyclization of S-alkylated adducts of lithiated alkoxyallenes with isothiocyanates (1-aza-1,3,4-Trienes) into pyrroles and of [1,5]-sigmatropic rearrangement into conjugated 2-aza-1,3,5-Trienes with subsequent closure into dihydropyridine ring (through 6π-electrocyclization).
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New transformations of 2-Aza-1,3,5-Trienes by the action of t-BuOK-THF-DMSO
Russian Journal of Organic Chemistry, 2011Co-Authors: N. A. Nedolya, Ol'ga G. Volostnykh, Ol'ga A. Tarasova, Alexander I. Albanov, Boris A. TrofimovAbstract:2-Aza-1,3,5-Trienes have become readily accessible due to discovery and systematic studies of reactions of allenic and acetylenic carbanions with isothiocyanates [1, 2]. These compounds are universal precursors of new 2,3-dihydropyridines [3–7], pyridines [5], 5,6-dihydropyridin-2(1H)and -3(4H)-ones [6], pyridine2(1H)-thiones [7], cyclobuta[1,2-b]pyrroles [4, 7, 8], and seven-membered nitrogen-containing heterocycles [9–11]. In particular, we found that 2-aza-1,3,5-Trienes obtained from, e.g., methoxyor 1-(1-ethoxyethoxy)allene and isopropyl isothiocyanate undergo fast transformation in t-BuOK–THF (0°C, 10 min) or t-BuOK– THF–DMSO (–30°C, 30 min) into previously inaccessible 3(6)-methoxy[9] and 3(6)-(1-ethoxyethoxy)substituted [10] 7-methyl-2-methylsulfanyl-4,5-dihydro-3H-azepines and 2-methyl-3H-azepines whose ratio depends on the nature of substituent in position 3 (6), as well as on the reaction conditions. On the other hand, conjugated 2-aza-1,3,5-triene synthesized from dilithium derivative of 2-methyl-5-(prop-2-yn-1-yl)thiophene and isopropyl isothiocyanate reacted with potassium tert-butoxide in THF–DMSO to give exclusively 2-methyl-6-(5-methylthiophen-2-yl)-3H-azepine [11]. Analogous reaction of 2-aza-1,3,5-Trienes derived from allenes or acetylenes and unbranched alkyl isothiocyanates could open the way to previously unknown 6(3)-alkyl-substituted dihydroazepines and/or azepines. However, deprotonation of such aza Trienes has not been reported so far, and the result of this transformation is difficult to predict. While continuing studies in this field, we were the first to react α-lithiated methoxyallene with butyl isothiocyanate with a view to obtain previously unknown N-(but-1-ylidene)-2-methoxy-1-methylsulfanylbuta-1,3-dien-1amine (I, 2-aza-1,3,5-triene) (Scheme 1) and convert it into 6(3)-ethylazacycloheptadienes and -Trienes (Scheme 2). It is known that 1-aza-1,3,4-Trienes derived from branched sec-alkyl isothiocyanates undergo smooth isomerization (via [1,5]-H shift) into the corresponding 2-aza-1,3,5-Trienes at room or moderately elevated temperature (~60°C, 10–20 min) [1, 9– 11]. Analogous sigmatropic rearrangement of 1-azaISSN 1070-4280, Russian Journal of Organic Chemistry, 2011, Vol. 47, No. 1, pp. 141–145. © Pleiades Publishing, Ltd., 2011. Original Russian Text © N.A. Nedolya, O.G. Volostnykh, O.A. Tarasova, A.I. Albanov, B.A. Trofimov, 2011, published in Zhurnal Organicheskoi Khimii, 2011, Vol. 47, No. 1, pp. 141–145.
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unexpected transformations of 1 aza 1 3 4 Trienes in alcoholic potassium hydroxide new classes of aza dienes
Russian Journal of Organic Chemistry, 2011Co-Authors: N. A. Nedolya, Ol'ga G. Volostnykh, Alexander I. Albanov, O A Tarasova, Boris A. TrofimovAbstract:Aza dienes [1, 2] and aza Trienes [2, 3] are useful and important intermediates in the synthesis of both heterocyclic and open-chain polyfunctionalized compounds. We have discovered reactions of isothiocyanates with carbanions derived from alkenes [4], allenes [5], acetylenes [6], and butadienes [7], which have become an inexhaustible source of various aza diene and aza triene systems [8, 9]. Methyl N-ethyl-2-methoxybuta-2,3-dienimidothioate (I, 1-aza-1,3,4-triene) is a precursor of 1-ethyl-3methoxy-2-methylsulfanyl-1H-pyrrole (II), 5-methoxy-2-methyl-6-methylsulfanyl-2,3-dihydropyridine (III) [8], and 3-methoxy-2-methylsulfanyl-4,5-dihydro-3H-azepine (IV) [10] and is readily available from lithiated methoxyallene and ethyl isothiocyanate (Scheme 1). Using compound I as an example we performed for the first time a simple and convenient synthesis of unusual aza dienes, hemiaminal ethers with rare heteroatom substituents. It was found that treatment of 1-aza-1,3,4-triene I (without isolation from the reaction mixture) with a solution of potassium hydroxide in methanol at room temperature resulted in the formation of previously unknown methyl (Z)-2-methoxy-N-(1-methoxyethyl)but-2-enimidothioate (V) (Scheme 1) as a mixture of syn and anti isomers in ~45% yield (unoptimized). A probable reaction path involves isomerization of 1-aza-1,3,4-triene I into 2-aza-1,3,5-triene VI, addition of methanol at the C=N bond of VI, and subsequent [1,5]-H shift in adduct VII thus formed (Scheme 2). ISSN 1070-4280, Russian Journal of Organic Chemistry, 2011, Vol. 47, No. 1, pp. 146–149. © Pleiades Publishing, Ltd., 2011. Original Russian Text © N.A. Nedolya, O.A. Tarasova, O.G. Volostnykh, A.I. Albanov, B.A. Trofimov, 2011, published in Zhurnal Organicheskoi Khimii, 2011, Vol. 47, No. 1, pp. 146–149.
B A Trofimov - One of the best experts on this subject based on the ideXlab platform.
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structural reorganization of allyl benzyl and propargylsulfanyl substituted 2 aza 1 3 5 Trienes in t buok thf dmso access to rare functionalized 2 thiazolines
Tetrahedron Letters, 2014Co-Authors: N. A. Nedolya, O A Tarasova, A I Albanov, B A TrofimovAbstract:Abstract Treatment of (allyl-, benzyl-, and propargylsulfanyl)-substituted 2-aza-1,3,5-Trienes, which are readily accessible from lithiated methoxyallene, isopropyl isothiocyanate, and allyl, benzyl, or propargyl bromide, respectively, with t-BuOK in THF/DMSO resulted in the unexpected formation of 2-thiazoline derivatives along with seven-membered azaheterocycles [in the case of (allyl- and benzylsulfanyl)-substituted 2-aza-1,3,5-Trienes]. An unprecedented structural reorganization of the azaTrienes into 2-thiazolines presumably occurs via α-deprotonation of the substituents at the sulfur atom followed by intramolecular [1,5]-cyclization. Deprotonation of the ketimine fragment of the same molecule followed by [1,7]-electrocyclization resulted in azepine ring formation.
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simultaneous synthesis of 4 5 dihydro 3h azepines and 3h azepines bearing alkoxy and alkylsulfanyl substituents through metallation of 2 aza 1 3 5 Trienes by t buok
Journal of Organometallic Chemistry, 2011Co-Authors: N. A. Nedolya, Ol'ga G. Volostnykh, O A Tarasova, A I Albanov, B A TrofimovAbstract:Abstract A new range of alkoxy- and alkylsulfanyl-substituted 4,5-dihydro-3 H -azepines and 3 H -azepines have simultaneously been obtained from conjugated 2-aza-1,3,5-Trienes by treatment with t -BuOK under mild reaction conditions (THF/DMSO, ∼−30 °C, 30 min). One-pot synthesis of 1-aza-1,3,4-Trienes from α-lithiated alkoxyallenes, isopropyl isothiocyanate and alkyl iodides, followed by the thermally induced sigmatropic [1,5]-H shift, easily leads to starting 2-aza-1,3,5-Trienes. The reaction proceeds via generation and [1,7]-electrocyclization of azatrienyl anions and represents a novel simple approach to both azacycloheptadienes and azacycloheptaTrienes.
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Reactions of heterocumulenes with organometallic reagents: XVII. One-pot synthesis of alkoxy and (alkylsulfanyl)-substituted pyrroles and 2,3-dihydropyridines from aliphatic isothiocyanates and lithiated alkoxyallenes
Russian Journal of Organic Chemistry, 2011Co-Authors: N. A. Nedolya, O A Tarasova, A I Albanov, L. Brandsma, B A TrofimovAbstract:A fundamentally new approach was developed to designing pyrrole and dihydropyridine rings from available allenes and isothiocyanates involving a single preparative stage. Applying the reaction of lithiated alkoxyallenes with aliphatic isothiocyanates we have synthesized previously unknown 1-alkyl(cycloalkyl) pyrroles and 2,3-dihydropyridines with rare alkoxy- and alkylsulfanyl substituents. It was proved that the five- and six-membered azaheterocycles formed as a result of competing reactions of direct intramolecular cyclization of S-alkylated adducts of lithiated alkoxyallenes with isothiocyanates (1-aza-1,3,4-Trienes) into pyrroles and of [1,5]-sigmatropic rearrangement into conjugated 2-aza-1,3,5-Trienes with subsequent closure into dihydropyridine ring (through 6π-electrocyclization).
Ze-jian Xue - One of the best experts on this subject based on the ideXlab platform.
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Stereoselective synthesis of conjugated Trienes via 1,4-palladium migration/Heck sequence.
Chemical communications (Cambridge England), 2020Co-Authors: Ze-jian Xue, Bin-bin Zhu, Chen-guo Feng, Guo-qiang LinAbstract:Conjugated Trienes are ubiquitous structures in natural products and organic functional molecules. An efficient 1,4-palladium migration/Heck sequence was developed for the highly stereoselective synthesis of trisubstituent 1,3,5-Trienes, which were found to undergo easy E/Z isomerization in the presence of light.
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stereoselective synthesis of conjugated Trienes via 1 4 palladium migration heck sequence
Chemical Communications, 2020Co-Authors: Ze-jian Xue, Bin-bin Zhu, Chen-guo Feng, Guo-qiang LinAbstract:Conjugated Trienes are ubiquitous structures in natural products and organic functional molecules. An efficient 1,4-palladium migration/Heck sequence was developed for the highly stereoselective synthesis of trisubstituent 1,3,5-Trienes, which were found to undergo easy E/Z isomerization in the presence of light.
