Year: 2024
Type: article
Abstract: While substituted adamantanes have widespread use in medicinal chemistry, materials science, and ligand design, the use of diamantanes and higher diamondoids is limited to a much smaller number. Selective functionalization beyond adamantane is challenging, as the number of very similar types of C-H bonds (secondary, 2°, and tertiary, 3°) increases rapidly, and H atom transfer does not provide a general solution for site selectivity. We report a method using pyrylium photocatalysts that is effective for nanodiamond functionalization in up to 84% yield with exclusive 3° selectivity and moderate levels of regioselectivity between 3° sites. The proposed mechanism involving photooxidation, deprotonation, and radical C-C bond formation is corroborated through Stern-Volmer luminescence quenching, cyclic voltammetry, and EPR studies. Our photoredox strategy offers a versatile approach for the streamlined synthesis of diamondoid building blocks.
Source: ACS Catalysis
Authors: Hoang T. Dang, Henry T. O’Callaghan, Mikayla M. Wymore, Jennifer Suarez, David B. C. Martin
Institution: University of Iowa
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: MRI: Acquisition of a Hybrid Quadrupole Mass Spectrometer with an Ultra-High Pressure Chromatograph, MRI: Acquisition of a 400-MHz NMR Spectrometer with Nitrogen-Cooled Cryoprobe, G1953762453, Acquisition of a 600-MHz Nuclear Magnetic Resonance Spectrometer, New Photocatalytic Coupling Reactions to Prepare Bioactive Molecules
OpenAlex ID: W4392385839