Synthesis and Detecting Properties of New Linear and Macrocyclic O,O′-Aminobenzyl BINOL Derivatives

A series of O-halobenzyl and O,O′-bis(halobenzyl) derivatives of (S)-1,1′-bi(2-naphthol) (BINOL) have been synthesized, and their amination in the presence of palladium and copper catalysts has been studied. As a result, a new family of macrocyclic and linear BINOL derivatives with various substituents at the oxygen atoms, including those possessing additional chiral centers, has been obtained. The synthesized compounds have been evaluated for their detecting properties toward metal cations by UV and fluorescence titration. Among the obtained open-chain derivatives, a potential fluorescent sensor for Al³⁺ cations has been found due to multiple emission enhancement. In addition, a fluorescent molecular probe for Hg²⁺ and Al³⁺ has been identified. Among the macrocyclic derivatives, the compound with the longest trioxadiamine linker can be used as a molecular probe for Mg²⁺ and Ca²⁺ ions due to fluorescence enhancement with a red shift, as well as for Al³⁺ and Hg²⁺ ions due to strong fluorescence enhancement without change of the position of the emission maximum.