This feature review is focused on recent key applications of commonly used transition-metal Cp-type catalysts for C–H bond functionalizations.

Five new disubstituted 2,6-thioaryl-BODIPY dyes were synthesized via selective aromatic electrophilic substitution from commercially available thiophenols. The analysis of the photophysical properties via absorption and emission spectroscopy showed unusually large Stokes shifts for BODIPY fluorophores (70–100 nm), which makes them suitable probes for bioimaging. Selected compounds were evaluated for labelling primary immune cells as well as different cancer cell lines using confocal fluorescence microscopy.

This article describes a practical and sustainable carbon nanotube–CuFe₂O₄-catalyzed borylation reaction of alkenes and alkynes that operates with low catalytic loading (0.05 mol%), under air, and allows recycling of the heterogeneous catalyst.

Herein, we report the Rh‐catalyzed [2 + 2 + 2] cycloaddition of linked bis(diynes) Ar‐C≡C‐C≡C‐(CH ₂ ) ₃ ‐C≡C‐C≡C‐Ar with quinones for the rapid and efficient assembly of rigid structures containing bis(arylethynyl)naphthoquinones or anthraquinones using microwave radiation. The photophysical properties of the products were investigated, including absorption, emission, transient absorption (TA) spectroscopy, and singlet oxygen luminescence studies. However, the quinones did not exhibit photoluminescence or detectable singlet oxygen luminescence. Computational analysis via density functional theory (DFT) was performed to elucidate the electronic and structural factors influencing their behavior. Moreover, reductive methylation of one of the bis(arylethynyl)naphthoquinones ( 3aa ) generated the fluorescent bis(methoxy) naphthalene derivative 4aa ( Φ _f = 0.53). However, 4aa underwent photooxidation in air under sunlight via reaction with ¹ O ₂ , which it sensitized, leading to ring opening of the bis(methoxy)arene ring.