Naslov
Hydroxymethylaniline photocages for carboxylic acids and alcohols

Autori
Škalamera, Đani ; Blažek Bregović, Vesna ; Antol, Ivana ; Bohne, Cornelia ; Basaric, Nikola

Izvornik
Journal of organic chemistry (0022-3263) 82 (2017), 23; 12554-12568

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
anilines, carbocation, laser flash photolysis, photocage, photochemistry, protective groups

Sažetak
Ortho-, meta- and para-Hydroxymethylaniline methyl ethers 3-5-OMe and acetyl derivatives 3- 5-OAc were investigated as potential photocages for alcohols and carboxylic acids, respectively. The measurements of photohydrolysis efficiency showed that the decaging from ortho- and meta-derivatives takes place efficiently in aqueous solution, but not for the para-derivatives. Contrary to previous reports, we showthat the meta-derivatives are better photocages for alcohols, whereas ortho- derivatives are better protective groups for carboxylic acids. The observed differences were fully disclosed by mechanistic studies involving fluorescence measurements and laser flash photolysis (LFP). Photoheterolysis for the para-derivatives does not take place, whereas both meta- and ortho-derivatives undergo heterolysis and afford the corresponding carbocations 3-C and 4-C. The ortho-carbocation 4-o-C was detected byLFP in aqueous solution (λmax = 410 nm, τ ≈ 90 μs). Moreover, spectroscopic measurements for the meta-acetyl derivative 3-m-OAC indicated the formation of cation in the excited state. The application of ortho- aniline derivative as protective group was demonstrated by synthesizing several derivatives of carboxylic acids. In all cases, the photochemical deprotection was accomplished in high yields (>80%). This mechanistic study fully rationalized photochemistry of aniline photocages which is important for design of new photocages and has potential for synthetic, biological and medicinal applications.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

Napomena
This work is financed by the Croatian Academy of Sciences (HAZU)

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