Synthesis and Optical Properties of 2-(Benzo[b]thiophene-3-yl)pyrroles and a New BODIPY Fluorophore (BODIPY=4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene)

Discovery of dioxo-benzo[b]thiophene derivatives as potent YAP-TEAD interaction inhibitors for treating breast cancer

Disruption of protein-protein interaction between transcriptional enhancer factor (TEA)-domain (TEAD; a transcription factor) and its co-activator Yes-associated protein (YAP)/ transcriptional co-activator with PDZ-binding motif (TAZ) is a potential therapeutic strategy against various types of solid tumors. Based on hit compound 8 and 9a, hydrazone derivatives with dioxo-benzo[d]isothiazole (9b-n) and oxime ester (10a-s) or amide derivatives (11a-r) with dioxo-benzo[b]thiophene were designed and synthesized as novel TEAD-YAP interaction inhibitors. Amide derivative 11q exhibited a higher potency in inhibiting TEAD-YAP reporter expression activity (IC₅₀ = 12.7 μM), endogenous target gene (e.g., CTGF and CYR61) expression, breast cancer cell growth (GI₅₀ = 3.2 μM), and anchorage-independent growth in soft agar. Molecular docking analysis suggested that the newly synthesized compounds bound to interface 2 of TEAD had lower docking scores compared to the compounds that bind to interface 3; moreover, they were predicted to overlap with YAP. Therefore, we identified 11q as an attractive therapeutic agent for treating solid tumors overexpressing YAP/TAZ.

8-[4-(2-Hydroxypropane-2-yl)phenyl]-1,3,4,4,5,7-hexamethyl-4-boron-3a,4a-diaza-S-indacene

During recent years, the BODIPY core became a popular scaffold for designing photoremovable protecting groups (PPG). In this paper, we report the synthesis of a new molecule—8-[4-(2-hydroxypropane-2-yl)phenyl]-1,3,4,4,5,7-hexamethyl-4-boron-3a,4a-diaza-S-indacene—by the treatment of meso-(4-CO2Me-phenyl)-BODIPY with excess of MeMgI. The product was characterized by 1H, 13C NMR and HRMS. The combination of BODIPY core with tertiary benzilyc alcohol might be promising for utilizing this molecule as visible light removable PPG.

Oxidative C-H/C-H Coupling of Dipyrromethanes with Azines by TiO2-Based Photocatalytic System. Synthesis of New BODIPY Dyes and Their Photophysical and Electrochemical Properties

Oxidative C-H/C-H coupling reactions of dipyrromethanes with azines in the presence of a heterophase oxidative photocatalytic system (O₂/TiO₂/visible light irradiation) were carried out. As a result of cyclization of obtained compounds with boron trifluoride etherate, new hetaryl-containing derivatives of 4,4-difluoro-4-boron-3a,4a-diaza-s-indacene were synthesized. For the obtained compounds, absorption and luminescence spectra, quantum yields of luminescence as well as cyclic volt-amperograms were measured.

NLOphoric benzyl substituted BODIPY and BOPHY: A comprehensive linear and nonlinear optical study by spectroscopic, DFT and Z-scan measurement

BOPHY (BPY) and BODIPY (BDY) dye bearing benzyl group (Bn) at 4,4' and 2,6 position respectively were synthesized and characterized. The fluorescence decay measurements were performed which reveal that benzyl BOPHY (Bn-BPY) has shorter fluorescence lifetime compared to benzyl BODIPY (Bn-BDY). The difference in transition dipole moment is found to be 6.93 and 11.3 D for Bn-BDY and Bn-BPY respectively in toluene. The molecular electrostatic potential (MEP) plot shows Bn-BDY is more polarised compared to Bn-BPY. The nonlinear optical (NLO) property was evaluated using Z-scan measurement. The molecular electronic arrangement of Bn-BPY significantly affects the nonlinear absorption properties resulting into reverse saturable absorption (nonlinear absorption coefficient β = 0.256 × 10^-11 m/W). In contrast, the Bn-BDY displays saturable absorption character. The calculated third-order nonlinear susceptibility χ⁽³⁾ value is 12.23 × 10^-13 esu and 2.49 × 10^-13 esu for Bn-BDY and Bn-BPY respectively. The power limiting behaviour of Bn-BPY displays limiting threshold energy around 70 Jcm^-2 with clamped output at ~35 Jcm^-2.

Non-linear optical response of meso hybrid BODIPY: Synthesis, photophysical, DFT and Z scan study

Hybrid meso BODIPY dyes are synthesized and their linear and non-linear optical properties are studied. Time-resolved fluorescence lifetime decay is found to be identical for all dyes irrespective of meso substituents. The Z-scan experiment performed to calculate the nonlinear absorption coefficient (β) and third-order nonlinear susceptibility (χ³). Global hybrid (B3LYP and BHHLYP) and range-separated hybrid (CAM-B3LYP) functional with the basis set 6-311++G(d,p) was employed to determine the theoretical linear and non-linear optical properties. The computed β₀ value of all the three dyes was found to be superior to that of urea (βo = 0.371 × 10^-30 esu). Introduction of meso substituent directly affects the polarizability and second-order hyperpolarizability of the dyes. Thermal and reorientational effect of the investigated NLOphoric dyes were studied.

Crystal structure and synthesis of 3-(1H-pyrrol-2-yl)-1-(thio-phen-2-yl)propanone

The title compound, C11H9NOS, was obtained in an improved yield compared to previous literature methods. The mol-ecule is essentially planar with a maximum deviation of 0.085 Å from the mean plane through all non-H atoms. There is directive inter-molecular hydrogen bonding in the form of N-H⋯O hydrogen bonds with a distance of 2.889 (3) Å between the pyrrole amine and the ketone carbonyl O atom. The resulting hydrogen-bonding network defines a ribbon parallel to the a axis. These ribbons form offset stacks along the b axis.

Ferrocene catalysed heteroarylation of BODIPy and reaction mechanism studies by EPR and DFT methods

Spin cross-over experiment using EPR and DFT calculations show the radical formation.

Synthesis and Characterization of Far-Red/NIR-Fluorescent BODIPY Dyes, Solid-State Fluorescence, and Application as Fluorescent Tags Attached to Carbon Nano-onions

A series of π-extended distyryl-substituted boron dipyrromethene (BODIPY) derivatives with intense far-red/near-infrared (NIR) fluorescence was synthesized and characterized, with a view to enhance the dye's performance for fluorescence labeling. An enhanced brightness was achieved by the introduction of two methyl substituents in the meso positions on the phenyl group of the BODIPY molecule; these substituents resulted in increased structural rigidity. Solid-state fluorescence was observed for one of the distyryl-substituted BODIPY derivatives. The introduction of a terminal bromo substituent allows for the subsequent immobilization of the BODIPY fluorophore on the surface of carbon nano-onions (CNOs), which leads to potential imaging agents for biological and biomedical applications. The far-red/NIR-fluorescent CNO nanoparticles were characterized by absorption, fluorescence, and Raman spectroscopies, as well as by thermogravimetric analysis, dynamic light scattering, high-resolution transmission electron microscopy, and confocal microscopy.

2-(1-Hydroxypropyn-2-yl)-1-vinylpyrroles: the first successful Favorsky ethynylation of pyrrolecarbaldehydes

1-Vinylpyrrole-2-carbaldehydes react with acetylene at atmospheric pressure in a NaOH/EtOH/DMSO system at 7-10 °C to afford 2-(1-hydroxypropyn-2-yl)-1-vinylpyrroles in 53-94% yield. Thus, the first base-mediated direct ethynylation of pyrrolecarbaldehydes with free acetylene under modified conditions of the Favorsky reaction has been implemented to pave an expedient route to important biomolecules containing a pyrrole ring.

Nonlinear optical properties of multipyrrole dyes

The nonlinear optical properties of a series of pyrrolic compounds consisting of BODIPY and aza-BODIPY systems are investigated using 532 nm nanosecond laser and the Z-scan technique. Results show that 3,5-distyryl extension of BODIPY to the red shifted MeO₂BODIPY dye has a dramatic impact on its nonlinear absorption properties changing it from a saturable absorber to an efficient reverse saturable absorbing material with a nonlinear absorption coefficient of 4.64 × 10^-10 m/W. When plotted on a concentration scale per mole of dye in solution MeO₂BODIPY far outperforms the recognized zinc(II) phthalocyanine dye and is comparable to that of zinc(II) tetraphenylporphyrin.

Structural modification strategies for the rational design of red/NIR region BODIPYs

The structure–property relationships of red/NIR region BODIPY dyes is analyzed, so that trends in their photophysical properties can be readily compared.