Observations on the Synthesis of Photochromic Naphthopyrans

Gabbutt, Christopher D.; Heron, B. Mark; Instone, Alicia C.; Thomas, David A.; Partington, Steven M.; Hursthouse, Michael B.; Gelbrich, Thomas

doi:10.1002/ejoc.200390176

Cited by 84 publications

(67 citation statements)

References 39 publications

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“…Arguably the most important class of organic photochromic dye used within the ophthalmic lens industry today are the 2,2‐diaryl‐2 H ‐naphtho[1,2‐ b ]pyrans,3, 18 particularly the indeno‐fused subclass 15. It is for this reason that we have chosen such a photochromic dye from the patent literature to illustrate the applicability of our technology.…”

Section: Resultsmentioning

confidence: 99%

The use of poly(alkylene oxide)s to achieve fast and controlled photochromic switching in rigid matrices

Malic

Evans

2012

J. Polym. Sci. A Polym. Chem.

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We report a conjugation system for the enhancement of photochromic dye performance in rigid matrices using widely available, cheap, chemically robust and compatible polymeric starting materials, namely poly(propylene oxide) (PPO) and poly(1,2‐butylene oxide). Conjugation of these soft (low Tg) polymers to an indeno‐fused naphthopyran photochromic dye, in a telechelic geometry, gives access to a wide range of accelerated and tuned fade speeds (decoloration) via variation in molecular weight. The t1/2 and t3/4 fade speeds for PPO conjugates (polymer molecular weights ranging between ca. 425 and 2000) are accelerated by 35–58 and 51–76%, respectively, compared with the nonconjugated control dye. Longer oligomers provide faster decoloration approaching that obtained in solution. The stability of the polyethers allows functionalization using a wide variety of chemistries, including harsh acid catalyzed transformations, providing an overall facile synthesis of photochromic dye‐polymer conjugates in high yield and purity. In addition, these polymers give easy access to conjugates with star‐type architectures, which provide an even further improvement in performance compared with their linear counterparts with less conjugated polymer needed per dye to achieve a given fade speed. © 2012 Commonwealth of Australia. J Polym Sci Part A: Polym Chem, 2012

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Section: Resultsmentioning

confidence: 99%

The use of poly(alkylene oxide)s to achieve fast and controlled photochromic switching in rigid matrices

Malic

Evans

2012

J. Polym. Sci. A Polym. Chem.

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“…Non-commercial propargylic alcohols 3c,d were prepared by a known procedure from ketones 7c,d. [21] Alcohols 3 were then tentatively converted into the corresponding carbonates. Alcohol 3a was successfully converted into the intermediate carbonate 8a prior to nucleophilic substitution with alcohol 5 to afford 9a.…”

Section: Resultsmentioning

confidence: 99%

Triazolyl Derivatives for Acidic Release of Alcohols

Mondon¹,

Delatouche²,

Bachmann

et al. 2011

Eur J Org Chem

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New triazolyl-based carbonates and ethers have been investigated as potential alcohol-releasing systems under mild acidic conditions. Triazolyl carbonates could not be prepared because of their apparent instability, whereas ethers were successfully obtained. The rate of hydrolysis of these ethers ramged from a few hours to several days. A theoretical investigation demonstrated that the acidic release of alcohols from triazole derivatives proceeds first by protonation of the tri-

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“…21 A carbocation generated by the protonation of the propynol and following loss of water acts as an important intermediate to interact with 2-naphthol, then continues to undergo the Claisen rearrangement, tautomerisation to the allenyl naphthol, a 1,5-hydrogen shift and finally a 6p electrocyclisation to complete the sequence to afford the 3H-naphtho[2,1-b]pyran. 22 The yields of 4d and 4e were relatively low, which may be explained by the resonance-stabilized carbocation affected by diethylamino groups at the para positions of the phenyl groups. Obviously, the positive charge was delocalized throughout the resonance system, which extended by pep conjugation (Scheme 2), and the selectivity of the reaction was decreased when reaction with 2-naphthol and then led to the low yield.…”

Section: Synthesis and Structuresmentioning

confidence: 99%