Tetrafluorobenzo-Fused BODIPY: A Platform for Regioselective Synthesis of BODIPY Dye Derivatives

Abstract

A novel route for the synthesis of unsymmetrical benzo-fused BODIPYs is reported using 4,5,6,7-tetrafluoroisoindole as a precursor. The reactivity of the 3,5-dibromo tetrafluorobenzo-fused BODIPY was investigated under nucleophilic substitution and Pd(0)-catalyzed cross-coupling reaction conditions. In addition to the 3,5-bromines, one α-fluoro group on the benzo-fused ring can also be functionalized, and an unusual homocoupling with formation of a bisBODIPY was observed. This new class of fluorinated BODIPYs could find various applications in medicine and materials.

Investigations on the Synthesis, Reactivity, and Properties of Perfluoro‐α‐Benzo‐Fused BOPHY Fluorophores

“…Treatment of BOPHY 1 with 10 equivalents of bromine in chloroform [7a,19] led to the formation of 3,8‐dibrominated BOPHY 2 in 72 % yield, as shown in Scheme 1. BOPHY 2 was recrystallized from dichloromethane/methanol and directly used in reactivity studies, as shown in Schemes 2 and 3.…”

Synthesis, Reactivity, and Properties of a Class of π-Extended BODIPY Derivatives

“…Although the reaction mechanism is still not fully understood right now, we propose a singlet electron transfer reaction between electron-deficient Ex-BODIPY 2b and electron-rich phenethylamine or 4-methylbenzenethiolate anion, which gave an anionic radical intermediate 2b . A previous report also found that aniline was used as a reducing agent to give the electron-deficient BODIPY dimer …”

“…A previous report also found that aniline was used as a reducing agent to give the electron-deficient BODIPY dimer. 11 X-ray crystallographic analysis of 7 and 6b allowed the unambiguous characterization of both unexpected products. Both 7 and 6b showed classical BODIPY structure features (Table S1), and the newly formed C−C single bonds at 3,5positions have the same lengths of 1.49 and 1.50 Å (Figure 2).…”

β-AlkenylBODIPY Dyes: Regioselective Synthesis via Oxidative C–H Olefination, Photophysical Properties, and Bioimaging Studies

“…Among them, elegant research progress has been made on regioselective functionalization at the 3(5)-position of the BODIPY chromophore. − While the 2,6-(β)­positions of the BODIPY core bear the least positive charge and are most susceptible to electrophilic attack, many β-functionalized BODIPYs have thus been synthesized from 1,3,5,7-tetramethyl-substituted BODIPY derivatives, where methyl groups block other possible reaction sites and enhance the overall electronegativities. For example, several 2-alkenyl- and 2,6-dialkenyl-1,3,5,7-tetramethyl-BODIPYs were prepared directly from a 1,3,5,7-tetramethyl-BODIPY via palladium-mediated C–H functionalization reactions by Burgess and co-workers .…”