Year: 2026
Type: preprint
Abstract: The formation of linchpins is a powerful strategy for increasing molecular complexity. Chalcogenonium salts have become valuable intermediates for molecular diversification, owing to their exceptional chemoselectivity in arene C–H functionalization and a synthetic versatility comparable to that of halides and pseudohalides. Sulfonium group introduction through an isohypsic process from S(IV) precursors requires activation with strong acids or anhydrides. Here, we report the direct synthesis of selenonium salts from bench-stable Se(III) cationic selenuranes using a simple dump-and-stir protocol. The transformation proceeds under air at ambient temperature and requires no exogenous activators. Mechanistic investigations reveal high sensitivity to electronic effects (ρ = −10), whereas site selectivity is determined by the rate-limiting deprotonation step (kH/kD = 2.3). The method is scalable to 10.0 mmol (>6.2 g) and provides direct access to selenonium salts derived from complex molecules. The resulting selenonium salts serve as versatile linchpins for photochemical, nucleophilic, and transition-metal-catalyzed transformations, enabling late-stage molecular diversification.
Source: ChemRxiv
Institution: University of Vienna
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7212077544