Arylazoindazole photoswitches

Travieso-Puente, Raquel

Arylazoindazole photoswitches : facile synthesis and functionalization via SNAr substitution / Raquel Travieso-Puente ... [et al.]. -- A straightforward synthetic route to arylazoindazoles via nucleophilic aromatic substitution is presented. Upon deprotonation of the NH group, a C(6)F(5-)substituted formazan undergoes facile cydization as a result of intermolecular nucleophilic substitution (SNAr). This new class of azo photoswitches containing an indazole five-membered heterocycle shows photochemical isomerization with high fatigue resistance. In addition, the Z-isomers have long thermal half-lives in the dark of up to several days at room temperature. The fluorinated indazole group offers a handle for further functionalization and tuning of its properties, as it is shown to be susceptible to a subsequent, highly selective nucleophilic displacement reaction.

In Journal of the American Chemical Society. -- Washington : The American Chemical Society, 2017. -- ISSN 0002-7863. -- ISSN 1520-5126. -- Vol. 139, no. 9 (2017), pp. 3328-3331