An array of pyridine-ester enolate based organoboron complexes has been designed and synthesized via a one-pot cascade of Pd-catalyzedα-arylation and BF2complexation.The rapid structure-activity relationship(SAR)stud...An array of pyridine-ester enolate based organoboron complexes has been designed and synthesized via a one-pot cascade of Pd-catalyzedα-arylation and BF2complexation.The rapid structure-activity relationship(SAR)studies indicated that unsymmetrical N,O-chelated BF2complexes were highly fluorescent in solid state,and exhibited large Stokes shifts,excellent photostability,along with insensitivity to p H.Theα-aryl group could not only modulate the electronic effect but also inhibit the intermolecularπ-πstacking to promote the aggregation-induced emission(AIE)effect.DFT calculations and experiments identified that the intramolecular charge transfer properties of these N,O-chelates could be switched by the modification of substituents,resulting tunable fluorescence wavelengths.Furthermore,post-complexation modification was accomplished,including Suzuki-Miyaura cross-coupling,Buchwald-Hartwig amination,oxidative cleavage,along with a unique triple substitution reaction involving propargyl Grignard reagents.The exemplificative application of dimethylamine substituted boron complex as a reversible acidic vapor sensor was also demonstrated.展开更多
基金grateful for the support by the National Natural Science Foundation of China(Nos.21702013,22271010)。
文摘An array of pyridine-ester enolate based organoboron complexes has been designed and synthesized via a one-pot cascade of Pd-catalyzedα-arylation and BF2complexation.The rapid structure-activity relationship(SAR)studies indicated that unsymmetrical N,O-chelated BF2complexes were highly fluorescent in solid state,and exhibited large Stokes shifts,excellent photostability,along with insensitivity to p H.Theα-aryl group could not only modulate the electronic effect but also inhibit the intermolecularπ-πstacking to promote the aggregation-induced emission(AIE)effect.DFT calculations and experiments identified that the intramolecular charge transfer properties of these N,O-chelates could be switched by the modification of substituents,resulting tunable fluorescence wavelengths.Furthermore,post-complexation modification was accomplished,including Suzuki-Miyaura cross-coupling,Buchwald-Hartwig amination,oxidative cleavage,along with a unique triple substitution reaction involving propargyl Grignard reagents.The exemplificative application of dimethylamine substituted boron complex as a reversible acidic vapor sensor was also demonstrated.
