BODIPY Dye for Light-initiated Ni-catalyzed C-N Cross-Coupling Reaction

Author

Chinedu Benedicth Okoro, Eastern Illinois UniversityFollow

Graduate Program

Chemistry

Degree Name

Master of Science (MS)

Semester of Degree Completion

Spring 2025

Thesis Director

Hongshan He

Thesis Committee Member

Zhiqing Yan

Thesis Committee Member

Michael W. Beck

Thesis Committee Member

Cesar A. Ortiz-Ledon

Abstract

Over the past years, Traditional Buchwald-Hartwig amination relies on costly Pd catalysts and high temperature, limiting sustainability and scalability. To overcome this drawback, photoactivated C-N cross-coupling reactions, which incorporate photocatalysts (PC) and a less expensive nickel system, have emerged as a promising alternative. Currently, organic photocatalysts are favored for sustainable processes, but the use of either high-energy UV light or blue light as a light source raises concerns due to potential substrate degradation and biological safety risk. To address these challenges, this work reports the development of the first white-light-activated BODIPY-functionalized ligand (4-Py-BDP) for Ni-catalyzed C–N cross-coupling reactions. This system achieves efficient C–N bond formation at room temperature, yielding up to 84%. The Photophysical characterization of 4-Py-BDP revealed strong absorption at 504 nm (ε = 98,084 M⁻¹ cm⁻¹), emission at 518 nm, and a fluorescence lifetime of 1.88 ns in DCM. The photocatalyst enabled effective coupling between electron-deficient aryl iodides and secondary amines with good to excellent yields. The preliminary studies with mass spectroscopy, UV-VIS, fluorescence spectroscopy, and ¹H NMR showed that the formation of a Ni–amine complex appears to be a key intermediate for the amine and iodobenzene derivatives coupling reaction. The reaction mechanism proceeds via the in-situ generation of [Ni(4-Py-BDP)(amine)₃Br₂] complex to photoinduced reduction of [Ni(4-Py-BDP)(amine)₃Br₂] to Ni(I) via Förster resonance energy transfer (FRET). This Ni(I) consequently proceeds the reaction through Ni(I) – Ni(0) – Ni(II) cycle.

Recommended Citation

Okoro, Chinedu Benedicth, "BODIPY Dye for Light-initiated Ni-catalyzed C-N Cross-Coupling Reaction" (2025). Masters Theses. 5083.
https://thekeep.eiu.edu/theses/5083