Phthalazines. XV. Ring transformation of phthalazines into naphthalenes by means of inverse-electron-demand Diels-Alder reaction.

Oishi, Etsuo; Taido, N.; Iwamoto, Kaoru; Miyashita, Akira; Higashino, Takeo

doi:10.1248/cpb.38.3268

Cited by 25 publications

(14 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A highly effected silver-catalysed formal inverse electron-demand Diel's Alder (IEDDA) reaction of phthalazine 136 and siloxy alkynes 137 has been reported [94,95]. The reactions provided ready access to a wide range of siloxynaphthalenes 139 and anthracenes which are formed in good to high yields, under mild reaction conditions using low catalyst loadings (Scheme 38).…”

Section: Reaction With Acetylinic Compoundsmentioning

confidence: 99%

Recent Developments in Chemistry of Phthalazines

El-Azm¹,

Mahmoud²,

Hekal³

2014

Organic Chem Curr Res

View full text Add to dashboard Cite

El-Azm et al., Organic Chem Curr Res 2015, 4:1 http://dx.Hydrazines with 2-acyl benzoic acids: Kirill et al. [31] reported the cyclization of 2-nitro-5-chloro phenylhydrazine27 with acyl benzoic acids 28 yielded 2-(2-nitro-5-chlorobenzene)-4-substituted phthalazin-1-ones 29 (Scheme 7).Lukacs and Simig [61] adopted a novel method for the synthesis of phthalazine derivatives 32 via the reaction of benzophenones30 with chromium (VI) oxide in a mixture of acetic anhydride and sulphuric acid followed by cyclization of the products with hydrazine hydrate in refluxing ethanol (Scheme 8).Hydrazine with 1,2-diester:The dimethylphthalate derivative 33 reacted with hydrazine to yield the desired phthalhydrazide34 which undergo chlorination with phosphorus oxychloride to give 35. Subsequent treatment with sodium methoxide afforded the methoxychloride 36 [62] (Scheme 9). Hydrazines with Phthalides: Chloroformylation of 3-methoxy benzoic acid 37 and subsequently radical bromination of 38 produced 39 in good yield. Treatment with triphenyl phosphine gave 40 and wittig olefination with 3,5-dichloro-4-pyridine carboxaldehyde 41 afforded the phthalide 42. Hydrazine cyclization of 42 resulted phthalazine derivative 43 [42] (Scheme 10). Cockcroft et al. [12] synthesized the phthalazinone derivative 47 according the following (Scheme 11). AbstractThis review highlights the methods used for the synthesis of phthalazine derivatives and fused phthalazinones. Their reactivity and synthetic importance were investigated. Phthalazine derivatives can be used as building blocks for heterocycles as well as fused heterocyclic compounds. Scheme 1: Synthesis of phthalazinone derivatives 2 and 5 Scheme 2: Synthesis of phthalazinone derivatives 7-9. Reagents and conditions: (a) CHCl 3 , reflux, 5 h, 51%; (b) hydrazinehydrate, EtOH, addition at rt and then reflux, 90˚C, 2 h, 71%; (c) MeI, KOBu t , DMF, 30 min, 80%; (d) LiOH, THF:MeOH:water (1:1:1), rt, 8-10 h, 81%. Scheme 3: Synthesis of phthalazin(2H)-1-one 11, 12 Scheme 4: Synthesis of 2-[1-(4-oxo-3,4-dihydrophthalazin-1-yl)alkyl]-1Hisoindole-1,3-(2H)-diones Scheme 5: Synthesis of 1,4-disubstituted phthalazinylpiperazine derivatives 21 Scheme 6: One-pot Synthesis of thiadiazinyl-phthalazine-1,4-diones 24 and 26 Scheme 7: Synthesis of 4-substituted phthalazin-1-ones 29. Scheme 8: Synthesis of phthalazine derivatives 32 Scheme 9: Hydrazinolysis of dimethylphthalate derivative 33 Citation: El-Azm FSMA, Mahmoud MR, Hekal MH (2015) Recent Developments in Chemistry of Phthalazines. Organic Chem Curr Res 1:132. Scheme 23: Synthesis of 1H-pyrazolo [1,2-b] phthalazin-5,10-dione derivatives 92 Scheme 24: A plausible mechanism for the synthesis of 1H-pyrazolo[1,2-b] phthalazine-5,10-diones 95 Scheme 25: Synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives 97. Scheme 28: Synthesis of 1-{[(1H-1,2,3-triazol-4-yl)methoxy]phenyl}-1Hpyrazolo[1,2-b] phthalazine-5,10-dione derivatives 104 Scheme 30: Synthesis of 2H-indazolo[1,2-b] phthalazine-triones 107 Scheme 29: Synthesis of 2H-indazolo[2,1-b]pht...

show abstract

Section: Reaction With Acetylinic Compoundsmentioning

confidence: 99%

Recent Developments in Chemistry of Phthalazines

El-Azm¹,

Mahmoud²,

Hekal³

2014

Organic Chem Curr Res

View full text Add to dashboard Cite

show abstract

“…Oishi et al. have reported the formation of 1‐substituted naphthalenes in the IEDDA reactions of 1‐substituted phthalazines with enamines or ynamines at elevated temperatures and in the presence of electron‐withdrawing groups on the phthalazines . The work of Wegner et al.…”

Section: Introductionmentioning

confidence: 99%

“…[7][8][9] Oishi et al have reported the formation of 1-substituted naphthalenes in the IEDDA reactions of 1-substituted phthalazines with enamines or ynamines at elevated temperatures and in the presence of electron-withdrawing groups on the phthalazines. [10] The work of Wegner et al described, for the first time, Lewis acid catalyzed IEDDA reactions of 1,2diazines. [11][12][13] A novel dihydroborantherene was synthesized and used as a bidentate Lewis acid catalyst that activates the phthalazine by lowering the energy of its LUMO.…”

Section: Introductionmentioning

confidence: 99%

Elucidation of the Mechanism of Silver‐Catalyzed Inverse Electron‐Demand Diels‐Alder (IEDDA) Reaction of 1,2‐Diazines and Siloxy Alkynes

et al. 2019

View full text Add to dashboard Cite

Density functional theory (DFT) calculations were utilized to reveal the effect of highly efficient transition metal catalysis in inverse electron demand Diels‐Alder (IEDDA) reactions. The silver‐catalyzed IEDDA reactions of 1,2‐diazines and siloxy alkynes were investigated to highlight the effect of the catalyst and its mode of action. Two different reaction pathways, concerted and stepwise, were explored as well as the uncatalyzed reaction. Computations elucidate the details of the highly efficient Ag catalyst in IEDDA reaction, and are consistent with previous experimental studies. The mode of action for the catalyst is fully revealed and its specific effect on the regioselectivity/specificity of the reaction is established.

show abstract

“…Therefore, only one dienophile is known to react with unsubstituted pyridazine, 5 a few more to react with phthalazine 1. 6 Herein we describe for the first time an IEDDA reaction of an unsubstituted phthalazine catalyzed by a bidentate Lewis acid, 5,10-dimethyl-5,10-dihydroboranthrene (7). 7 The (1) (a) Nicolaou, K. C.; Snyder, S. A.; Montagnon, T.; Vassilikogiannakis, G. 781.…”

mentioning

confidence: 99%

“…Therefore, only one dienophile is known to react with unsubstituted pyridazine, 5 a few more to react with phthalazine 1. 6 Herein we describe for the first time an IEDDA reaction of an unsubstituted phthalazine catalyzed by a bidentate Lewis acid, 5,10-dimethyl-5,10-dihydroboranthrene (7). 7 The idea of the catalysis of the IEDDA reaction of 1,2-diazines is based on the following rationale: a bidentate Lewis acid may complex the vicinal nitrogen atoms and thus withdraw electron density from the diazine.…”

mentioning

confidence: 99%