Naslov
Photochemistry of hydroxymethylaniline derivatives as potential photocages

Autori
Basarić, Nikola ; Škalamera, Đani ; Blažek Bregović, Vesna ; Bohne, Cornelia

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
26th IUPAC Symposium on Photochemistry / Osaka, Japan / - Osaka, 2016, 5C08-5C08

Skup
26th IUPAC Symposium on Photochemistry

Mjesto i datum
Osaka, Japan, 03.04.2016. - 08.04.2016

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
photochemistry ; photocages ; anilines

Sažetak
Development of new photocages has become increasingly important due to their numerous potential applications in biology and medicine [1]. One of the aspects that an ideal photocage should have is fast release of the functional group, taking place in a photochemical rather than a subsequent thermal step. Photoexcitation of such a system allows for temporal and spatial control of the decaging process. However, most of the photocages that have been used to date have relied on the o-nitrobenzylalcohols where decaging is intrinsically slow. Wang et al. have recently reported an elegant example of photocage for alcohols based on the photochemical cleavage of m-hydroxymethylaniline ethers [2]. Although not explicitly reported, the reaction probably proceeds via a heterolytic cleavage in S1 and carbenium ion intermediates. Moreover, the decaging reaction represents an example of the meta-effect in photochemistry [3]. A recent theoretical account explained photochemical reactivity of meta- opposed to para-aniline derivatives. Whereas heterolytic cleavage of para-derivatives takes place in the ground state and gives stable carbocations, meta-derivatives react from S1 where the intrinsic reactivity is governed by the position of a conical intersection between the S1 ad S0 [4]. However, experimental evidence to support this theoretical work is lacking. Herein we present a systematic experimental investigation of the photochemical reactivity of a series of anilines bearing at the ortho- meta- or para-position protected or non-protected hydroxymethyl group. Anilines 1-8 were synthesized and their photochemical reactivity studied by preparative irradiation and isolation of photoproducts, fluorescence spectroscopy and laser flash photolysis. Carbocations formed from the ortho-derivatives were spectroscopically characterized and their reactivity with nucleophiles investigated. Our experimental results support the theoretical investigation [4] and show the potential of ortho- and meta- derivatives for the development of new photocages for alcohols or carboxylic acids.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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