Diverse reactivity of carbenes and silylenes towards fluoropyridines

Abstract

The reaction of IDipp with C₅F₅N led to functionalization of all three carbon atoms of the imidazole ring with HF₂⁻ as the counter-anion (1). Reactivity with 2,3,5,6-tetrafluoropyridine gives only C–F bond activation leaving C–H bonds intact (5b). The reaction of SIDipp with C₅F₅N in the presence of BF₃ afforded the ring cleavage product (3). Analogous reactions with silylene led to oxidative addition at the Si(II) center.