CCXVIII.—Styrylpyrylium salts. Part IX. Colour phenomena associated with benzonaphtha- and dinaphtha-spiropyrans

Dickinson, Robert A.; Heilbron, I. M.

doi:10.1039/jr9270001699

Cited by 17 publications

(12 citation statements)

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“…The carbonyl carbon again forms an acid-catalyzed carbocation to eventually generate a styryl pyrilium salt. Similar styryl pyrilium salts of 2-hydroxy-1-naphthaldehyde by condensation with dibenzylketone (Dickinson, Heilbron, & O'Brien, 1928) and salicylaldehyde have been reported in the literature (Dickinson & Heilbron, 1927;Heilbronn, Heslop, & Irving, 1933). The proposed mechanism was also supported by the crystal structure of [3-(2,β-thiodimethylene)[2-(2-hydroxy)-1-benzylvinyl)]benzo pyrilium chloride] (5) which was obtained by the condensation of 4-tetrahydrothiopyranone and salicylaldehyde.…”

Section: Mechanism For the Formation Of 33′-azadimethylene Dibenzosupporting

confidence: 75%

Tumor suppressive activities of solvatochromic 3,3′‐azadimethylene dinaphthospiropyran in colon cancer model

et al. 2020

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Spiropyrans have been extensively investigated because of their thermo‐ and photochromic characteristics, but their biotherapeutic properties have not been explored much. We report anti‐proliferative properties of a novel 3,3′‐azadimethylene dinaphthospiropyran 11. Dibenzospiropyrans and dinaphthospiropyrans were synthesized by a simple and expedient method using acid‐catalyzed aldol condensation of salicylaldehyde and 2‐hydroxy‐1‐naphthaldehyde, respectively, with cyclic ketones. Together with structural elucidation by 2D NMR and X‐ray crystallography studies, we provide a putative mechanism for their formation. Compound 11 showed solvatochromism and exhibited altered spectral characteristics depending on the pH. In acidic conditions, 11 remains in open form, whereas upon alkalinization it reverts back to closed form. Based on the in vitro anti‐proliferative activity in H441, HCT‐116, MiaPaCa‐2, and Panc‐1 cancer cell lines, 11 was submitted to further investigation. It reduced HCT116 colonosphere formation and demonstrated induction of caspase cascade, suggesting apoptosis. In vitro proliferation assays also suggested that HCl and trifluoroacetate salts of 11 are more effective. Treatment of mice carrying HCT‐116 xenografts with 11 (5 µg/day, intraperitoneal for 3 weeks) suppressed tumor growth by 62%. Overall, the results reveal a new series of structurally complex, but relatively easy to synthesize molecules of which compound 11 represents a lead for anticancer development.

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Section: Mechanism For the Formation Of 33′-azadimethylene Dibenzosupporting

confidence: 75%

Tumor suppressive activities of solvatochromic 3,3′‐azadimethylene dinaphthospiropyran in colon cancer model

et al. 2020

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“…The principle way for obtaining spiropyrans (Scheme A) was introduced nearly a century ago and consisted of an acid-catalyzed condensation of symmetric dialkyl ketones with o -hydroxyarenealdehydes . We posit that, under the acidic conditions, transiently formed flavylium turned into its enol-like form, thereby acting as a nucleophile in the aldol condensation with the o -hydroxyarenealdehyde to give a spiropyran product (Scheme A) .…”

Section: Resultsmentioning

confidence: 99%

One-Pot Aldol Cascade for the Preparation of Isospiropyrans, Flavylium Salts, and bis-Spiropyrans

et al. 2020

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We probed tandem aldol condensations of sixteen o-hydroxyacetophenones, carrying electron-withdrawing and -donating groups at positions 4 and 5, using five molar equivalents of SiCl 4 in anhydrous ethanol. Substrates carrying electron-withdrawing groups (EWGs) (0 < ∑σ > 0.63) populated the equilibria with isospiropyrans (12−74% yield), while those carrying electron-donating groups (EDGs) (∑σ < −0.31) gave flavylium salts (50−80%) or thermochromic bis-spiropyrans (73%). The results are of interest for developing novel organic materials possessing switchable photochromic and thermochromic characteristics.

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“…Originally noticed in 1927 by Dickinson and Heilbron for their thermochromic properties, spiropyrans were only characterized as photoswitches in 1952 by Fischer and Hirshberg . Since then, this family of compounds has been extensively studied and reviewed in a number of papers. − The spiropyran structure is commonly considered as formed by a benzopyran moiety linked to an indoline part by a spiro bond (Figure f).…”

Section: Motion From Photochromic Molecular Switchesmentioning

confidence: 99%

“…38 Even if it is possible to avoid this side reaction by replacing that labile hydrogen with an alkyl moiety, this switch is not as fatigue-resistant as dithienylethenes, and its applications have been therefore comparatively limited. 100 Originally noticed in 1927 by Dickinson and Heilbron for their thermochromic properties, 108 spiropyrans were only characterized as photoswitches in 1952 by Fischer and Hirshberg. 109 Since then, this family of compounds has been extensively studied and reviewed in a number of papers.…”

Section: Introduction To Photochromic Molecular Switchesmentioning

confidence: 99%

Design of Collective Motions from Synthetic Molecular Switches, Rotors, and Motors

et al. 2019

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Precise control over molecular movement is of fundamental and practical importance in physics, biology, and chemistry. At nanoscale, the peculiar functioning principles and the synthesis of individual molecular actuators and machines has been the subject of intense investigations and debates over the past 60 years. In this review, we focus on the design of collective motions that are achieved by integrating, in space and time, several or many of these individual mechanical units together. In particular, we provide an in-depth look at the intermolecular couplings used to physically connect a number of artificial mechanically active molecular units such as photochromic molecular switches, nanomachines based on mechanical bonds, molecular rotors, and light-powered rotary motors. We highlight the various functioning principles that can lead to their collective motion at various length scales. We also emphasize how their synchronized, or desynchronized, mechanical behavior can lead to emerging functional properties and to their implementation into new active devices and materials.

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CCXVIII.—Styrylpyrylium salts. Part IX. Colour phenomena associated with benzonaphtha- and dinaphtha-spiropyrans

Cited by 17 publications

References 0 publications

Tumor suppressive activities of solvatochromic 3,3′‐azadimethylene dinaphthospiropyran in colon cancer model

Tumor suppressive activities of solvatochromic 3,3′‐azadimethylene dinaphthospiropyran in colon cancer model

One-Pot Aldol Cascade for the Preparation of Isospiropyrans, Flavylium Salts, and bis-Spiropyrans

Design of Collective Motions from Synthetic Molecular Switches, Rotors, and Motors

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