Cyclization of 3-(arylchalcogeno)propenoyl chlorides. 2. Chalcogen and substituent control in the regiochemistry of intramolecular acylation. Preparation of benzo[b]telluropyrones

Detty, Michael R.; Murray, Bruce J.

doi:10.1021/ja00342a041

Cited by 80 publications

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“…These results prompted us to examine the reaction of 1 with acetone. The addition of the salts (1) to dry acetone at room temperature gave the 1-acetonyl-1H-isocheromenes (9). However, the yield of the products was very low except for the 1-acetonyl-3-tert-butyl-1H-isoselenocheromenes (9Aa).…”

Section: Resultsmentioning

confidence: 99%

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Studies on Tellurium-Containing Heterocycles. Part 20. Reactions of 2-Benzoselenopyrylium Salts and 2-Benzotelluropyrylium Salts with Nucleophiles: Formation of 1-Functionalized 1H-Isoselenochromenes and 1H-Isotellurochromenes

Sashida

Ohyanagi

2004

CHEMICAL & PHARMACEUTICAL BULLETIN

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Recently, the chemistry of the selenopyrylium [2][3][4] and telluropyrylium salts, [2][3][4][5] six-membered cationic heteroaromatics containing a selenium or tellurium atom, in both fields of organic synthesis and the chemical transformation of organotellurium and organoselenium compounds, has attracted considerable attention. Both of the monocyclic pyrylium 6,7) and 1-benzopyrylium salts [8][9][10] containing these atoms have been prepared, and the chemistry of these compounds has been reviewed. We have also previously reported the practical and facile preparation [11][12][13] and the reactions 11,14,15) of these 1-benzopyrylium salts. More recently, we succeeded in preparing 16) the stable 2-benzotelluropyrylium 17) and 2-benzoselenopyrylium salts, 18) structural isomers of them; the former is a previously unknown heterocyclic ring system. Therefore, this paper deals with the results of the examination of the reactivity of these novel 2-benzopyryliun salts with various nucleophiles using the stable compounds, 3-tert-butyl and (or) 3-unsubstituted derivatives as easily available pyrylium salts. The differences in the reactivity of these pyrylium salts containing a tellurium or selenium atom have received most of our attention thus far. Results and DiscussionReduction of Pyrylium Salts 23) were reported. In all cases, the major products are 4H-pyrans. The one-electron reduction of them when treated with zinc dust [24][25][26] in a degassed aprotic solvent gives the bichalcogenopyran derivatives via the pyranyl radical intermediates. We have previously described that the LiAlH 4 reduction of the 1-benzotelluropyrylium salts 11) and 1-benzoselenopyrylium salts, 14) the regioisomers of the title compounds, afforded a mixture of the corresponding 2H-and 4H-chromenes, respectively; the latter was the major product. In order to compare these behaviors, we first examined the hydride reduction of the 2-benzopyrylium salts (1). The reduction of 1A and 1B with LiAlH 4 in diethyl ether at 0°C afforded the 1H-isoselenochromenes (2A) and 1H-isotellurochoromenes (2B) in moderate yields as the sole products, respectively. The use of THF as a solvent almost gave similar results. The pyrylium salts (1) were also reduced by DIBAL-H to give the 1H-isochromenes (2) in quantitative yields. These compounds (2) were identical with the authentic samples, 16) which were the precursors for the synthesis of the corresponding pyrylium salts (1A) and (1B). The 3-tertbutyl-2-benzopyrylium salts (1Aa) and (1Ba) reacted with excess zinc dust in acetonitrile at 0°C under an argon atmosphere to give 1,1Ј-bis(tert-butylisochromenyl) (3Aa) and (3Ba) in 18 and 15% yield as the sole characterized products, respectively. The MS spectrum of compound 3Aa suggested the diselenide molecular formula of C 26 H 30 Se 2 as it measured a molecular ion at m/zϭ502 ( 80 Se) and the expected isotope pattern for Se 2 . The base peak was m/zϭ251, which was a half of the molecular ion. In addition the HR-MS of 3Aa showed the exact molecular formula. There was no c...

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Section: Resultsmentioning

confidence: 99%

“…Both of the monocyclic pyrylium 6,7) and 1-benzopyrylium salts [8][9][10] containing these atoms have been prepared, and the chemistry of these compounds has been reviewed. We have also previously reported the practical and facile preparation [11][12][13] and the reactions 11,14,15) of these 1-benzopyrylium salts.…”

mentioning

confidence: 99%

Studies on Tellurium-Containing Heterocycles. Part 20. Reactions of 2-Benzoselenopyrylium Salts and 2-Benzotelluropyrylium Salts with Nucleophiles: Formation of 1-Functionalized 1H-Isoselenochromenes and 1H-Isotellurochromenes

Sashida

Ohyanagi

2004

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…The regiochemistry of cyclization of 3-(arylchalcogeno)propenoic acids and acid chlorides has been explored as a convenient route to obtain 4H-benzo[b]chalcogenopyran-4-ones [1]. The ring formation of the chalcogenopyrones is considered to take place via intramolecular electrophilic ortho substitution of the aryl group (Scheme I) and is sensitive to the nature of the M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 2 chalcogen atom bound to it as well as the position and electronic influence of the substituents of the benzene ring.…”

Section: Introductionmentioning

confidence: 99%

Electrophilic substitution of acetyltrimethylsilane with tellurium(IV) halides: A synthetic route to 3-methyl-5-(trimethylsilyl)-1,2-oxatellurol-1-ium halides

Misra

Chauhan

Srivastava

et al. 2015

Journal of Organometallic Chemistry

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“…[1][2][3][4][5][6][7] Among the functionalized vinyl chalcogenides, those containing a Michael acceptor, like an ester, [8][9][10][11][12] a keto [13][14][15][16][17][18][19] or a nitrile group [20][21][22] at the adjacent sp 2 carbon are of greatest interest since they combine the chemical reactivity of the vinyl chalcogenides and the vinyl acceptor group.…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3][4][5][6][7]10,[23][24][25] Despite the simplicity of experimental procedure and high regio-and stereoselectivity, this method shows some disadvantages, such as, the use of stinking, volatile and toxic thiophenol, unstable and air sensitive tellurolate and selenolate anions, use of long heating time and inert atmosphere. The "in situ" generation of organyl thiolate, 26 selenolate 10,26,27 and tellurolate anions 10,12,27,28 has solved the unpleasant smell problem. Unfortunately, these improvements were not extended to alkynes bearing electronwithdrawing groups and have not eliminated the use of organic solvents and inert atmosphere.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of beta-phenylchalcogeno-alpha, beta-unsaturated esters, ketones and nitriles using microwave and solvent-free conditions

Lenardão

Silva

Mendes

et al. 2007

J. Braz. Chem. Soc.

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Cyclization of 3-(arylchalcogeno)propenoyl chlorides. 2. Chalcogen and substituent control in the regiochemistry of intramolecular acylation. Preparation of benzo[b]telluropyrones

Cited by 80 publications

References 0 publications

Studies on Tellurium-Containing Heterocycles. Part 20. Reactions of 2-Benzoselenopyrylium Salts and 2-Benzotelluropyrylium Salts with Nucleophiles: Formation of 1-Functionalized 1H-Isoselenochromenes and 1H-Isotellurochromenes

Studies on Tellurium-Containing Heterocycles. Part 20. Reactions of 2-Benzoselenopyrylium Salts and 2-Benzotelluropyrylium Salts with Nucleophiles: Formation of 1-Functionalized 1H-Isoselenochromenes and 1H-Isotellurochromenes

Electrophilic substitution of acetyltrimethylsilane with tellurium(IV) halides: A synthetic route to 3-methyl-5-(trimethylsilyl)-1,2-oxatellurol-1-ium halides

Synthesis of beta-phenylchalcogeno-alpha, beta-unsaturated esters, ketones and nitriles using microwave and solvent-free conditions

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