Changjiang Yu

β-Formyl-BODIPYs from the Vilsmeier−Haack Reaction

A series of beta-formyl-BODIPYs 2 were synthesized in high yields from tetramethyl-BODIPYs 1 via the Vilsmeier-Haack reaction and were further functionalized using a Knoevenagel condensation to generate novel BODIPYs 3 and 4.

Synthesis and Functionalization of Asymmetrical Benzo-Fused BODIPY Dyes

A series of asymmetrical benzo-fused BODIPY dyes were synthesized from the Sonogashira coupling and nucleophilic substitution reactions on the 3-halogenated benzo-fused BODIPY, generated from readily available 3-halogeno-1-formylisoindoles in a two-step synthetic procedure. This novel BODIPY platform provides an easy path for the linking of BODIPY fluorophore to various desired functionalities as demonstrated in this work. Most of the resulting BODIPY dyes show long-wavelength absorption and fluorescence emission, with good fluorescence quantum yields and long fluorescence lifetimes.

Long wavelength red fluorescent dyes from 3,5-diiodo-BODIPYs

Amphiphilic and long wavelength red fluorescent dyes (4 and 7) were prepared from the Sonogashira coupling reactions of 3,5-diiodo-BODIPYs (1 and 6). One of these compounds, BODIPY 7, readily accumulated within human carcinoma HEp2 cells and was found to localize mainly within the endoplasmic reticulum (ER).

Highly Fluorescent BF2 Complexes of Hydrazine–Schiff Base Linked Bispyrrole

A series of BF2 complexes of hydrazine-Schiff base linked bispyrrole have been prepared from a simple two-step reaction from commercially available substances and are highly fluorescent in solution, film, and solid states with larger Stokes shift and excellent photostabilities comparable or even super to those of their BODIPY analogues. These resultant fluorescent dyes are highly susceptible to the postfunctionalization, as demonstrated in this work via the Knoevenagel condensation to introducing functionalities or tether groups to the chromophore.

β-Thiophene-Fused BF2-Azadipyrromethenes as Near-Infrared Dyes

A facile synthetic route to a new class of near-IR β-thiophene-fused BF2-azadipyrromethenes (aza-BDTPs) is presented. Sharp absorption and fluorescence emission bands at around 800 nm were observed for these highly photostable aza-BDTPs, with a large absorption coefficient and very low absorptions in the visible range from 700 to 380 nm.

Accessing near-infrared-absorbing BF2-azadipyrromethenes via a push-pull effect.

Novel aza-BODIPYs with significant bathochromic shifts were designed and synthesized by installation of strong electron-withdrawing groups on the para-positions of 1,7-phenyls and electron-donating groups on the para-positions of 3,4-phenyls. These dyes show strong NIR fluorescence emissions up to 756 nm, and absorptions up to 720 nm.

Diversity-Oriented Facile Access to Highly Fluorescent Membrane-Permeable Benz[c,d]indole N-Heteroarene BF2 Dyes

A diversity-oriented one-pot synthesis of a series of membrane-permeable BF2-rigidified benz[c,d]indole N-heteroarene BBN and BBC dyes has been achieved from the condensation of two commercial components (benz[c,d]indol-2-one and a set of N-heteroarene derivatives that can be selected from thousands of commercially available sources) and the subsequent in situ BF2 complexation reaction. These dyes enjoy a set of excellent photophysical properties including the large Stokes shift, high solution and solid-state fluorescence, and excellent photostabilities.

Synthesis of pyrrolyldipyrrinato BF2 complexes by oxidative nucleophilic substitution of boron dipyrromethene with pyrrole

Direct oxidative nucleophilic substitution of the 3-hydrogen of BODIPY dyes by pyrrole has been developed under reflux condition under oxygen, from which a series of pyrrolyldipyrrinato BF(2) complexes 1a-h, as extended BODIPYs, have been synthesized. Most of these BODIPYs show strong fluorescence emissions at wavelengths over 600 nm in six solvents of different polarity. Removal of the BF(2) group from BODIPY 1e gave the corresponding free base pyrrolyldipyrrin 7 as an analog of the natural product prodigiosin, in high yield.

Conformation-Restricted Partially and Fully Fused BODIPY Dimers as Highly Stable Near-Infrared Fluorescent Dyes

A set of highly stable conformation-restricted partially and fully fused BODIPY dimers (α,β-cyclohexadiene-fused and α,β-benzene-fused dimers) were synthesized from a one-pot condensation of 2-formylpyrroles with α,β-cyclohexadiene-fused bipyrrole 3. Effective expansion of π-conjugation over these fused BODIPY dimers was observed by X-ray analysis, density functional theory (DFT) calculations, and electrochemical and optical measurements, as demonstrated by their strong absorption and emissions in the near-infrared (NIR) range (650 to 820 nm).

Regioselective and Stepwise Syntheses of Functionalized BODIPY Dyes through Palladium-Catalyzed Cross-Coupling Reactions and Direct C-H Arylations.

Regioselective and stepwise syntheses of a series of functionalized BODIPY dyes through palladium-catalyzed cross-coupling reactions and direct C-H arylations have been developed. In particular, this method allows the straightforward synthesis of 2,6-dibromo-3,5-diarylBODIPYs and 2-bromo-3-arylBODIPYs from polybrominated BODIPYs. The X-ray structure of intermediates 5a-c indicated that the palladium was first inserted into the C-Br bonds at 3,5-positions of brominated BODIPYs. The resulting 2,6-dibromo-substituted BODIPYs are potential long wavelength photosensitizers which are not easily accessible using previous methods.