Abstract
An array of pyridine-ester enolate based organoboron complexes has been designed and synthesized via a one-pot cascade of Pd-catalyzed α-arylation and BF2 complexation.The rapid structure-activity relation-ship(SAR)studies indicated that unsymmetrical N,O-chelated BF2 complexes were highly fluorescent in solid state,and exhibited large Stokes shifts,excellent photostability,along with insensitivity to pH.Theα-aryl group could not only modulate the electronic effect but also inhibit the intermolecular π-π stack-ing to promote the aggregation-induced emission(AIE)effect.DFT calculations and experiments identi-fied 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.
维普
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