Journal ArticleDOI
Furo-fused 2H-chromenes: synthesis and photochromic properties
TLDR
In this article, photochromic chromenes annulated with a furan ring have been synthesized, which lead to a mixture of linear and angular chromenes that is strictly related to the nature of the phenol.Abstract:
New photochromic chromenes annulated with a furan ring have been synthesized. Thus, suitable heterocyclic phenols react with different propargylic alcohols in acidic medium to give the corresponding ethers, which cyclize into benzopyrans by thermal Claisen rearrangement. This synthetic approach was found to lead to a mixture of linear and angular chromenes that is strictly related to the nature of the phenol. However, regiospecificity could be obtained by reacting β-phenylcinnamaldehyde, in refluxing aprotic nonpolar solvents, with titanium(IV) salts of the former phenols. Electrocyclization of intermediately generated o-quinoid structures occurs on the α position towards the heterocyclic junction. All compounds exhibit photochromic behavior at room temperature. Furo-fused benzopyrans are particularly interesting with respect to naphthopyran parents in view of the bathochromically shifted and broadened absorption spectra of photoinduced forms. This trend is confirmed by the spectral data of several hetero...read more
Citations
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Journal ArticleDOI
Spiropyrans: Synthesis, Properties, and Application. (Review)
TL;DR: In this article, the chemical properties of spiropyrans, including complexation of the open-chain isomers and cyclic forms, are examined. And the photochromic properties of the interfaces between phases are investigated.
Journal ArticleDOI
Multiaddressable Self-Assembling Organogelators Based on 2H-Chromene and N-Acyl-1,ω-amino Acid Units†
Saleh A. Ahmed,Xavier Sallenave,Frédéric Fages,Gudrun Mieden-Gundert,Walter M. Müller,Ute Müller,Fritz Vögtle,Jean-Luc Pozzo +7 more
TL;DR: Multiaddressable organogelators are 3,3-diphenyl-3H-naphtho[2,1-b]pyrans covalently linked to sodium N-acyl-11-aminoundecanoate that are shown to act as efficient gelators for polar organic fluids, and obviously they exhibit a thermosensitive answer as low molecular mass organogselators.
Journal ArticleDOI
Facile one-pot synthesis of photochromic pyrans.
Weili Zhao,Erick M. Carreira +1 more
TL;DR: In this paper, photochromic pyrans including [3H]naphtho[2,1-b]pyrans, [2H] naphthol or phenol derivatives in the presence of 5 mol % PPTS and 2 equiv of (MeO)3CH were synthesized in excellent yields through a facile one-pot procedure.
Journal ArticleDOI
A Simple and Versatile Strategy for Rapid Color Fading and Intense Coloration of Photochromic Naphthopyran Families.
TL;DR: A new simple and versatile strategy to substantially reduce the amount of the undesirable long-lived colored transoid-trans form by introducing an alkoxy group at the 1-position of azino-fused chromenes, i.e., 8H-pyranoquinazolines is found.
Journal ArticleDOI
Efficient photochemical merocyanine-to-spiropyran ring closure mechanism through an extended conical intersection seam. A model CASSCF/CASPT2 study.
TL;DR: The extended seam topology of the S2/S1 conical intersection and the coordinate of the branching space of theS1/S0 conical intersections are essential to explain the efficiency and high speed of this reaction.
References
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Book
Photochromism : molecules and systems
Heinz Dürr,Henri Bouas-Laurent +1 more
TL;DR: In this article, the authors proposed a photochromism based on pericyclic reactions and cycloaddition reactions involving 4n+2 electrons for the purpose of energy storage.
Journal ArticleDOI
Photochromism of Synthetic and Naturally Occurring 2H-Chromenes and 2H-Pyrans
Ralph S. Becker,Josef Michl +1 more
Book
Chromenes, chromanones, and chromones
TL;DR: Chromenes, Chromanones, and Chromones-Introduction (G. P. Ellis), 2H - and 4H -1-Benzopyrans (E. Schweizer and Deborah Meeder-Nycz).
Journal ArticleDOI
Synthesis and Reactions of 4-Chromanones
Hans-Joachim Kabbe,Arno Widdig +1 more
TL;DR: In this article, it was shown that the condensation of o-hydroxyacetophenone with aliphatic aldehydes and ketones in the presence of pyrrolidine leads to 4-chromanones in good yields.
Journal ArticleDOI
Studies on Acetylenic Compounds. XXXII. Ring Closure of Propargyl Ethers. (2).
Issei Iwai,Junya Ide +1 more
TL;DR: In this paper, a new synthetic method for various 4-substituted-3-chromenes was proposed, where phenyl propargyl ethers underwent intramolecular cyclization to give 4-chromene derivatives by heating with diethylaniline.