| The aim of the dissertation was to develop synthetic routes to bis(diacetylene)biphenylene 215, 4,5:6,7-dibenzocyclobutathionin (biphenylenothionin) 217 and biscyclobuta[c,g]phenanthrene (bi-3,4:5,6-phenanthrylene) 218 as well as the study of their physical and chemical properties. Bis(diacetylene)anthracene 216, the dimer of 1,8-diethynylanthracene 213, prepared 40 years ago by the group of Nakagawa, was more efficiently synthesized as a model compound to 215. Molecules 215 and 216 are considered as precursors to carbon-rich materials and were synthesized by oxidative alkyne-alkyne coupling reaction.; The first part of this dissertation introduces the initial concepts for synthesizing biphenylene and its dialkyl and dihalo derivatives as the basis to the successful total syntheses of 215 and 216, through similar protocoles: palladium/nickel-mediated couplings of protected acetylene to dihaloarenes (biphenylene and anthracene) followed by copper(II)-mediated oxidative coupling of the terminal acetylenes to afford the dimers 215 and 216 (second part). Attempts to synthesize the annelated thionin 217 through nucleophilic addition of sulfide ion to 1,8-diethynylbiphenylene will be presented. Preliminary results (GCMS) suggest a facile and expected extrusion of sulfur atom to give cycloocta[def]biphenylene.; This is followed by a theoretical discussion predicting the formation of bis(cyclobuta)phenanthrene 218 and our synthetic efforts directed towards the target are presented in the final part. |
