A One-Pot Entry to a Novel 3-H-benzo[d]pyrazolo[1,5-b]isothiazole Ring System

Vicini, Paola; Incerti, Matteo; Ferretti, Rocco; Zanardi, Franca

doi:10.1007/s11030-005-9011-3

Cited by 8 publications

(10 citation statements)

References 15 publications

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“…The phosphorus ylide obtained from the reaction between 2-aminobenzo[d]isothiazol-3-one (43) and (2) in the presence of (1) undergoes a smooth intramolecular Wittig-type reaction to produce, in a one-pot reaction, 3-Hbenzo[d]pyrazolo [1,5-b]isothiazole-2,3a-dicarboxylic acid dimethyl ester (49), a novel functionalized heterocyclic compound (Scheme 12) [83].…”

Section: Reaction Of Triphenylphosphine Dialkyl Acetylenedicarboxylamentioning

confidence: 99%

Synthesis and Reactions of Stabilized Phosphorus Ylides

Ramazani

Kazemizadeh

Ahmadi³

et al. 2008

COC

106

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Stabilized phosphorus ylides, versatile intermediates in synthetic organic chemistry can be prepared by the novel reaction of dialkyl acetylenedicarboxylates (DAAD), triphenylphosphine (TPP) and acids such as phenols, imides, amides, enols, oximes and alcohols. The reaction involves an intermediate formed by the 1:1 conjugate addition reaction of the TPP to DAAD and concomitant protonation of the intermediate by an acid leads to vinyltriphenylphosphonium salts. The salts are unstable intermediates and converted to stabilized phosphorus ylides via Michael addition reaction. The stabilized phosphorus ylides are able to take part in the normal intramolecular Wittig reactions but they are not generally able to participate in the normal intermolecular Wittig reactions. The intermolecular Wittig reactions of the ylides are observed only with highly electron-poor carbonyl groups such as indane-1,2,3-trione. The ylides are converted to electron-poor alkenes via elimination of TPP in solvent-free conditions. Almost all of the final products are valuable families of compounds. †Dedicated to Professor Issa Yavari on the occasion of his 59th birthday.

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Section: Reaction Of Triphenylphosphine Dialkyl Acetylenedicarboxylamentioning

confidence: 99%

Synthesis and Reactions of Stabilized Phosphorus Ylides

Ramazani

Kazemizadeh

Ahmadi³

et al. 2008

COC

106

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“…[3][4][5] In this context, recently, we have explored the one-pot reaction between 2-aminobenzo[d]isothiazol-3-one (ABO) 1 and dimethyl acetylenedicarboxylate in the presence of triphenylphosphine (PPh 3 ) that afforded a new functionalized tricyclic compound, namely 3-H-benzo[d]pyrazolo [1,5-b]isothiazole-2,3a-dicarboxylic acid dimethyl ester. 6 In our efforts to further exploit PPh 3 promoted reactions between 2-aminobenzo[d]isothiazol-3-one and activated acetylenes, we herein report a new synthesis of alkyl 4-amino-5-oxo-4,5-dihydrobenzo[f] [1,4]thiazepine-3-carboxylates 2 and 3 obtained, through heterocyclic ring expansion, from ABO and alkyl propiolates (Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

Synthesis and NMR spectral assignments of novel 1,4-benzothiazepine-5-one derivatives

Incerti

Acquotti

Sándor³

et al. 2009

Tetrahedron

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“…The phosphorus ylide obtained from the reaction between 2-aminobenzo[d]isothiazol-3-one (92) and DAAD (2) (94), a novel functionalized heterocyclic compound (Scheme 28) [123]. Quinolines are interesting synthetic targets because they act as building blocks for a large number of natural products.…”

Section: Reaction Of Triphenylphosphine Dialkyl Acetylenedicarboxylamentioning

confidence: 99%

Preparation of Stabilized Phosphorus Ylides via Multicomponent Reactions and Their Synthetic Applications

Ramazani

Kazemizadeh

2011

COC

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Triphenylphosphine (TPP), dialkyl acetylenedicarboxylates (DAAD), and acids such as phenols, imides, amides, enols, oximes and alcohols react with each other via a multicomponent reaction to produce stabilized phosphorus ylides. The reactions take place easily, through formation of intermediate formed by the Michael addition of the triphenylphosphine to dialkyl acetylenedicarboxylates and concomitant protonation of the intermediate by an acid leads to vinyltriphenylphosphonium salts. The salts are unstable intermediates and undergo a subsequent Michael addition leads to stabilized phosphorus ylides. In some cases ylide products are stable, but in other cases they cannot be isolated and appear to occur as intermediates on the pathway to an observed product. The stabilized phosphorus ylides are able to take part in the normal intramolecular Wittig reactions and produce a variety of heterocyclic or carbocyclic compounds, but they are not able to participate in the intermolecular Wittig reactions.

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A One-Pot Entry to a Novel 3-H-benzo[d]pyrazolo[1,5-b]isothiazole Ring System

Cited by 8 publications

References 15 publications

Synthesis and Reactions of Stabilized Phosphorus Ylides

Synthesis and Reactions of Stabilized Phosphorus Ylides

Synthesis and NMR spectral assignments of novel 1,4-benzothiazepine-5-one derivatives

Preparation of Stabilized Phosphorus Ylides via Multicomponent Reactions and Their Synthetic Applications

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