ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis and properties of macrocyclic diazene switch with binaphthalene unit attached via acrylamide linkers

Anna Kicková, Branislav Horváth, Lukáš Kerner, and Martin Putala

Department of Organic Chemistry, Comenius University in Bratislava, Mlynská dolina, 842 15 Bratislava, Slovakia

E-mail: putala@fns.uniba.sk

Abstract: 2,2′-Diiodo-1,1′-binaphthalene undergoes a tandem Heck reaction with methyl acrylate to afford methyl 2-(7H-dibenzo[c,g]fluoren-7-ylidene)acetate. As a consequence, the target macrocyclic diazene with binaphthalene unit attached via acrylamide linker was prepared by the stepwise building of acrylamide at a binaphthalene moiety, including the Doebner modification of the Knoevenagel condensation, and completed by oxidative macrocyclisation of aniline end-groups. Despite being an equimolar mixture of monomer and dimer, it exhibited remarkable changes in CD spectra due to reversible (E/Z) isomerisation of N=N diazene bonds upon irradiation at 365/465 nm. Although the dimer isomerises from (E) to (Z) isomer 7.4 times faster than the monomer, the latter’s contribution to the change in ellipticity at 307 nm in the photostationary state is 2.4 times greater.

Keywords: azo compounds – binaphthyl derivatives – chiroptical switches – memory devices – tandem Heck reaction

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-012-0247-y

Chemical Papers 67 (1) 101–109 (2013)