Cyclotribromoveratrylene in Synthesis of Porphyrin-Containing Polyphenols

Porphyrin-containing polyphenols bonded to a cycloveratrylene macrocycle as a molecular platform have been synthesized. Polyphenols were obtained by the Suzuki–Miyaura reaction between cyclotribromoveratrylene and a boryl derivative of N,N'-diporphyrinaniline and subsequent chemical transformations. In particular, demethylation of the reaction product containing peripheral methoxy groups and subsequent blocking of the phenol hydroxyls by two different acid-labile protecting groups—cyclobutyldicyclopropylmethyl and 1-perfluoroethylcyclohexyl—led to a target polyphenol, which was then used for the development of a new positive photoresist capable of forming patterns with a 16 nm resolution when exposed to radiation at a wavelength of 13.5 nm.