Highly Strained Tertiary sp3 Scaffolds: Synthesis of Functionalized Cubanes and Exploration of Their Reactivity under Pd(II) Catalysis

A series of chemically distinct, highly strained, activated cubane scaffolds were synthesized through optimization of the metal–halogen exchange reactions of iodinated cubane derivatives. This included the first reported successful attachment of both boron and phosphorus, key elements in potential transition-metal-catalyzed cross-coupling reactions, on the cubane scaffold. Additionally, Zn, Sn, Si, S, and various C-based systems were also attached in a high-yielding, one-pot reaction from readily available precursors. A comprehensive program investigating the reactivity of these tertiary cubane nucleophiles toward Suzuki–Miyaura, Negishi, and Stille cross-coupling methods, never previously reported with the cubane scaffold, is also described, but proved unsuccessful.