Diastereomer Resolution and Structural-Property Relationship of Phosphorus-Chirogenic Luminescent α-Aminophosphaphenanthrenes.

Exploring simple and efficient methods for the synthesis and resolution of diastereomers of chiral compounds with phosphorus stereogenic center is of great importance considering that the spatial configuration of chiral molecules has a significant impact on their physicochemical properties. In this work, eight α-aminophosphaphenanthrene derivatives with both phosphorus and carbon chiral centers, and different substituents were synthesized in high yields (≥ 88%) from Kabachnik-Fields multicomponent reaction of commercially available aldehydes, aniline derivatives, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), which were found to possess unique aggregation-induced emission (AIE) behavior. Facile resolution of the diastereomeric pairs of these eight phosphorus chirogenic compounds was achieved based on their significant solubility differences or distinct polarity. All eight pairs of single crystal structures for these α-aminophosphaphenanthrene diastereomers were obtained to reveal their different molecular spatial configurations, intramolecular and intermolecular interactions. Most importantly, the physicochemical properties of these diastereomers were compared, revealing that the CRPR/CSPS-isomers generally exhibited greater polarity, stronger luminescence intensity, and higher photochemical reactivity compared to the corresponding CRPS/CSPR-isomers. The facile synthesis and resolution of these phosphorus-chirogenic diastereomers, the unique luminescence property, together with the diastereomeric structure-dependent emission and photo-reactivity, would accelerate the development of phosphorus-chirogenic materials.