21372-42-9Relevant academic research and scientific papers
Oxidative Approach Enables Efficient Access to Cyclic Azobenzenes
Maier, Martin S.,Hüll, Katharina,Reynders, Martin,Matsuura, Bryan S.,Leippe, Philipp,Ko, Tongil,Sch?ffer, Lukas,Trauner, Dirk
supporting information, p. 17295 - 17304 (2019/11/03)
Azobenzenes are versatile photoswitches that have found widespread use in a variety of fields, ranging from photopharmacology to the material sciences. In addition to regular azobenzenes, the cyclic diazocines have recently emerged. Although diazocines have fascinating conformational and photophysical properties, their use has been limited by their synthetic accessibility. Herein, we present a general, high-yielding protocol that relies on the oxidative cyclization of dianilines. In combination with a modular substrate synthesis, it allows for rapid access to diversely functionalized diazocines on gram scales. Our work systematically explores substituent effects on the photoisomerization and thermal relaxation of diazocines. It will enable their incorporation into a wide variety of functional molecules, unlocking the full potential of these emerging photoswitches. The method can be applied to the synthesis of a new cyclic azobenzene with a nine-membered central ring and distinct properties.
ELECTROLYTIC REDUCTION OF o-NITROBENZYL THIOCYANATE IN BUFFERED SOLUTIONS ON MERCURY
Hlavaty, Jaromir
, p. 33 - 41 (2007/10/02)
The o-nitrobenzyl thiocyanate (I) behaves differently on the DME and on a large mercury pool electrode.Polarography did not give a sufficiently clear explanation of the reaction mechanism, only the preparative experiments yielded useful results.Whereas polarographic curves in solutions of Britton-Robinson buffer system with 50percent by vol. ethanol exhibit two cathodic waves within the pH region 1-12, corresponding according to their height ratio to an uptake of 4 e and 2 e respectively, the controlled potential preparation electrolysis (CPE) and coulometry results indicate a more complicated reaction path.In the CPE carried out at the concentration of I 1.10-2 mol/l the electroreductive splitting of CH2-SCN occurs as the first step.Nitrobenzyl radicals so formed react in the follow-up dimerization resulting in dibenzyl or toluene structures.Simultaneously or at a later stage the completion of the electrolytic reduction of the nitro group proceeds to the hydroxylamino group.In solution of 9>pH>1 the CPE of nitro compounds I takes place by an ECEC mechanism yielding dibenzodiazocine III, its N-oxide IV and 2,2'-dimethylazoxybenzene (V).In course of preparative electrolysis in strongly acidic medium 2-amino-benzo(1,3)-thiazine-1-oxide (II) is formed by an EC mechanism.
