Atroposelective Palladium-Catalyzed γ-C-H Olefination of BODIPYs

Abstract

Enantioenriched BODIPYs have emerged as a class of exceptionally valuable fluorophores, distinguished by their remarkable chiroptical properties and versatile applications in bioimaging, molecular sensing, and optoelectronic materials. The development of asymmetric catalytic methodologies for their synthesis represents a significant advancement in this field. Herein, we present a robust and efficient strategy for the Pd(II)-catalyzed atroposelective C-H olefination and desymmetrization at the γ-position of BODIPYs, facilitated by a thioether directing group and a chiral amino acid-derived ligand. This oxidative Heck-type reaction enables the direct synthesis of a wide array of axially chiral BODIPY derivatives with exceptional E-selectivity and outstanding enantioselectivities. The resultant chiral fluorophores exhibit tunable photophysical properties, including near-infrared emission and robust circularly polarized luminescence, and demonstrate excellent biocompatibility in live-cell imaging. This method establishes a comprehensive platform for the streamlined synthesis of axially chiral BODIPYs, thereby advancing their potential applications in cutting-edge photonic, biological, and optoelectronic technologies.

Keywords: Amino acids; Axial Chirality; BODIPYs; C–H activation; Palladium catalysis.