Diels–Alder Reaction of Isobenzofurans/Cyclopentadienones with Tetrathiafulvalene: Preparation of Naphthalene, Fluoranthene, and Fluorenone Derivatives

Diels–Alder reaction of 1,3-diarylbenzo­[<i>c</i>]­furan/cyclopentadienone with TTF followed by triflic acid mediated cleavage of the resulting adducts led to the formation of the respective 1,4-diaryl substituted naphthalenes, fluoranthenes, and fluorenones. The photophysical properties of representative diaryl-substituted hydrocarbons are also reported

Synthesis and photophysical properties of benzo[<i>c</i>]thiophene, <i>p</i>-phenylene-, triphenylamine-, and pyrene-based vinylenes

<p>An efficient synthesis of benzo[<i>c</i>]thiophenyl/<i>p</i>-phenylenyl/pyrenyl phosphonate esters has been achieved using ZnBr₂-catalyzed Michaelis–Arbuzov reaction of corresponding benzyl alcohol/bromides at room temperature. Horner–Wadsworth–Emmons reaction of the phosphonate esters with aryl/heteroaryl aldehydes in the presence of <i>t</i>-BuOK furnished the vinylenes in good yields. The absorption and emission characteristics of the synthesized vinylenes were also reported.</p

Synthesis of Annulated Arenes and Heteroarenes Involving Lewis Acid-Mediated Regioselective Annulation of Unsymmetrical 1,2-(Diaryl/diheteroarylmethine)dipivalates

A ZnBr₂-mediated regioselective annulation of unsymmetrical 1,2-diarylmethinedipivalates in DCM at room temperature led to the formation of annulated arenes and heteroarenes. The annulation of the dipivalate proceeds through the intermediacy of benzylic carbocations followed by intramolecular cyclization and subsequent aromatization to give the annulated products. The annulation methodology is highly efficient for the syntheses of anthracene as well as naphtho­[<i>b</i>]­thiophene analogues

Synthesis of Annulated Arenes and Heteroarenes Involving Lewis Acid-Mediated Regioselective Annulation of Unsymmetrical 1,2-(Diaryl/diheteroarylmethine)dipivalates

A ZnBr₂-mediated regioselective annulation of unsymmetrical 1,2-diarylmethinedipivalates in DCM at room temperature led to the formation of annulated arenes and heteroarenes. The annulation of the dipivalate proceeds through the intermediacy of benzylic carbocations followed by intramolecular cyclization and subsequent aromatization to give the annulated products. The annulation methodology is highly efficient for the syntheses of anthracene as well as naphtho­[<i>b</i>]­thiophene analogues

Synthesis of Annulated Arenes and Heteroarenes Involving Lewis Acid-Mediated Regioselective Annulation of Unsymmetrical 1,2-(Diaryl/diheteroarylmethine)dipivalates

A ZnBr₂-mediated regioselective annulation of unsymmetrical 1,2-diarylmethinedipivalates in DCM at room temperature led to the formation of annulated arenes and heteroarenes. The annulation of the dipivalate proceeds through the intermediacy of benzylic carbocations followed by intramolecular cyclization and subsequent aromatization to give the annulated products. The annulation methodology is highly efficient for the syntheses of anthracene as well as naphtho­[<i>b</i>]­thiophene analogues

Synthesis of Annulated Arenes and Heteroarenes Involving Lewis Acid-Mediated Regioselective Annulation of Unsymmetrical 1,2-(Diaryl/diheteroarylmethine)dipivalates

A ZnBr₂-mediated regioselective annulation of unsymmetrical 1,2-diarylmethinedipivalates in DCM at room temperature led to the formation of annulated arenes and heteroarenes. The annulation of the dipivalate proceeds through the intermediacy of benzylic carbocations followed by intramolecular cyclization and subsequent aromatization to give the annulated products. The annulation methodology is highly efficient for the syntheses of anthracene as well as naphtho­[<i>b</i>]­thiophene analogues

Synthesis of Annulated Arenes and Heteroarenes Involving Lewis Acid-Mediated Regioselective Annulation of Unsymmetrical 1,2-(Diaryl/diheteroarylmethine)dipivalates

A ZnBr₂-mediated regioselective annulation of unsymmetrical 1,2-diarylmethinedipivalates in DCM at room temperature led to the formation of annulated arenes and heteroarenes. The annulation of the dipivalate proceeds through the intermediacy of benzylic carbocations followed by intramolecular cyclization and subsequent aromatization to give the annulated products. The annulation methodology is highly efficient for the syntheses of anthracene as well as naphtho­[<i>b</i>]­thiophene analogues

Synthesis of Cyclo[<i>b</i>]fused Carbazoles via SnCl₄‑Mediated Domino Reaction of 2‑Indolylmethylpivalates with Arenes and Heteroarenes

A straightforward synthesis of aryl and heteroaryl-annulated cyclo­[<i>b</i>]­carbazoles has been developed via SnCl₄-mediated one-pot arylation, cyclization and aromatization reaction sequence from 3-acetyl/aroyl-2-pivaloyloxymethylindoles. The starting material is easily accessible from commercially available 2-methylindole via Friedel–Crafts acylation, bromination and pivaloylation. Remarkably, electron withdrawing/donating aroyl units including heterocyclic systems are well tolerated in the present domino reaction protocol. Furthermore, this methodology could be extended to the synthesis of dibenzofurocarbazole via bis-annulation of 2,5-bis­(2-pivaloyloxymethyl)­pyrrole

Diels–Alder Reaction of 1,3-Diarylbenzo[<i>c</i>]furans with Thiophene <i>S,S</i>-Dioxide/Indenone Derivatives: A Facile Preparation of Substituted Dibenzothiophene <i>S,S</i>-Dioxides and Fluorenones

One pot syntheses of substituted dibenzothiophene <i>S</i>,<i>S</i>-dioxides and fluorenones were successfully achieved by Diels–Alder reaction of benzo­[<i>c</i>]­furans with thiophene <i>S</i>,<i>S</i>-dioxides and indenones, respectively. Photophysical properties of representative seven- and nine-membered dibenzothiophene <i>S</i>,<i>S</i>-dioxide acenes were also reported

Diels–Alder Reaction of 1,3-Diarylbenzo[<i>c</i>]furans with Thiophene <i>S,S</i>-Dioxide/Indenone Derivatives: A Facile Preparation of Substituted Dibenzothiophene <i>S,S</i>-Dioxides and Fluorenones

One pot syntheses of substituted dibenzothiophene <i>S</i>,<i>S</i>-dioxides and fluorenones were successfully achieved by Diels–Alder reaction of benzo­[<i>c</i>]­furans with thiophene <i>S</i>,<i>S</i>-dioxides and indenones, respectively. Photophysical properties of representative seven- and nine-membered dibenzothiophene <i>S</i>,<i>S</i>-dioxide acenes were also reported