Synthese eines teilfluorierten Pentacens und Tetracens sowie ein Beitrag zur Synthese stickstoffhaltiger Pentacene mit alternierendem Substitutionsmuster

In the first project a symmetrical substituted fluorinated pentacene and an unsymmetrical substituted fluorinated tetracene were synthesized starting from bromodifluorbenzene. The highlight within this syntheses is the stepwise construction of one benzene ring of the acene core. Key steps are the SUZUKI-coupling of a pinacolboronic ester with a benzylbromides and an intramolecular nickel mediated reaction of an aryltriflate and an aldehyde. In the second project a literature known pyrimidinecarbaldehyde was synthesized and the reaction sequence was improved. With it in hand different substituted pyridopyrimidines could be synthesized in good yields via a HWE-photo cyclization-strategy which could be further derivatized in a diverse manner. The access to this compound class via the above mentioned sequence is new. Coupling reaction of two pyridopyrimidines was achieved by using HARTWIG-BUCHWALD-conditions to give nitrogen bridged bispyridopyrimidines in good yield. The thiomethyl substituted derivative could be further functionalized but the successful construction of the middle ring within the azapentacen failed.