Silyl- and Disilanyl-BODIPYs: Synthesis via Catalytic Dehalosilylation and Spectroscopic Properties

We describe herein the first synthesis of silyl- and disilanyl-BODIPYs through transition-metal-catalyzed dehalo-silylation of iodo-BODIPYs using a Pd(P(tBu)3)(2)/Et3N/toluene system. Various mono- and bis-silyl-BODIPYs, mono- and bis-disilanyl-BODIPYs and bis-BODIPYs linked by silylene and SiOSi groups were synthesized by using this straightforward method. Silyl-and disilanyl-substitution significantly modifies the spectroscopic properties of the BODIPY, in which the fluorescence quantum yields of the silyl- BODIPYs are remarkably increased, whereas the emission spectra of disilanyl-BODIPYs are red-shifted due to effective sigma(SiSi)-pi(BODIPY) conjugation.