The oxidation of 3,6-dehydrohomoadamantane (1) was the activation processes. Isomeric radical cations formed from different precursors can equilibrate with low barriers achieved under chemical (NO + BF 4 -/EtOAc, NO + OAc -/Ac 2 O, and NO + BF 4 -/CH 3 CN), photochemical (photoexcited 1,2,4,5-(2.0-11.7 kcal mol -1 ) and lead to common products. The computed and experimental adiabatic ionization potential of tetracyanobenzene), and electrochemical (Pt anode, CH 3 CN, NH 4 BF 4 ) conditions. Supporting ab initio [density functional adamantane shows that activation with NO + BF 4 -is also likely to occur through the adamantyl radical cation. Hence, the theory (BLYP) and Møller-Plesset perturbation theory (MP2)] computations utilizing standard basis sets, 6-31G* bonds need not be attacked directly by the electrophile in the C-H or C-C activation of alkanes with relatively low (optimizations) and 6-311+G* (single-point energy evaluations), agree with the experimental results implicating ionization potentials. the involvement of the same radical cation intermediates in
We investigated the reactions of 3,6-dehydrohomoada- [d] Institute of Organic Chemistry, Georg-August University of mantane (1) with NO ϩ BF 4 Ϫ , photoexcited TCB, and under Göttingen,