BOPYRENPY: A Modular Strategy toward Structurally Tunable Seven-Membered BF2‑Chelated Chromophores

A modular Knoevenagel condensation between 2-formylpyrroles and cyanomethylpyridine derivatives, followed by a chelation reaction, enables the synthesis of seven-membered BF2-chelated dyes, termed BOPYRENPY. This versatile strategy enhances structural diversity and functional applicability. In addition, our approach supports the late-stage incorporation of donor units via Suzuki coupling, allowing fine-tuning of fluorescence, Stokes shifts, and HOMO–LUMO energy levels. These findings establish BOPYRENPY as a versatile platform for next-generation chromophores based on 7-membered-ring dyes coordinated by BF2.