Flavin-dependent halogenases (FDHs) provide a biocatalytic approach for the site-selective halogenation of aromatic compounds, but their use in late-stage functionalization of peptides has remained li...

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Inspired by natural cryptic halogenation in C,C-bond formation, this study developed a synthetic approach combining biocatalytic bromination with transition-metal-catalyzed cross-coupling. Using the c...

Ready, set, brominate: RebH and engineered variant for bromination of peptidyl-Trp residues

Abstract. The functionalization of a hexa-peri-benzocoronene–fluoranthene hybrid with a K-type bay region is investigated. Bromination proceeds regioselect

The functionalization of C–H bonds enables the modification of complex molecules, often with the intention of forming compound libraries. The borylation of aryl C–H bonds is a widely used class of C–H...

Dinuclear aluminum-based triple-stranded helicates were functionalized through post-synthetic bromination with N-bromosuccinimide, enabling direct modification of a pre-assembled helical framework. By...

An electrochemical bromination of diazo compounds with CBr4 as a bromine source via convergent paired electrolysis has been developed, which affords α-bromo phosphonates as products in up to 96% yield...

Lead halide perovskite quantum dots (LHP QDs) CsPbX3 generate immense interest as narrow-band emitters for displays, lasers, and quantum light sources. All QD applications rely on suited engineering of surface capping ligands. The first generation of LHP QDs employed oleic acid/oleyl amine capping and have found only a limited use in photoredox catalysis. These catalysts have been reported to be unstable and decompose over the course of the reaction, thus reducing turnover numbers (TONs) and limiting their synthetic ability. Herein, the impact of eight distinct surface ligands on monodisperse CsPbBr3 QDs is reported, affording a thorough comprehension of their performance in photocatalytic C–H brominations. These efforts yielded QDs operating at extremely low catalyst loadings (<100 ppb) with TONs over 9,000,000 per LHP QD. We emphasize that the optimal catalytic performance requires increased QD surface accessibility without compromising the QD structural and colloidal integrity. Control experiments indicated that well-known photoredox catalysts such as Ir(ppy)3, Ru(bpy)3Cl2, or 4CzlPN are ineffective in the same reaction. Mechanistic studies reveal that the C–Br bond reduction in CH2Br2 is the rate-limiting step and is likely facilitated through interaction with the CsPbBr3 QD surface. This work outlines a holistic approach toward the design of practically useful photocatalysts out of QDs comprising structurally soft QD cores and dynamically bound capping ligands.

In this study meta-selective single-step bromination and chlorination reactions of pyridines and their derivatives are developed, with pyridinium radical cations as the key intermediates. A spin-densi...