Journal article
Authors list: Fokin, AA; Gunchenko, PA; Peleshanko, SA; von Ragué Schleyer, P; Schreiner, PR
Publication year: 1999
Pages: 855-860
Journal: European Journal of Organic Chemistry
Volume number: 1999
Issue number: 4
ISSN: 1434-193X
Publisher: Wiley
Abstract:
The oxidation of 3,6-dehydrohomoadamantane (1) was achieved under chemical (NO+BF4-/EtOAc, NO+OAc-/Ac2O, and NO+BF4-/CH3CN), photochemical (photoexcited 1,2,4,5-tetracyanobenzene), and electrochemical (Pt anode, CH3CN, NH4BF4) conditions. Supporting ab initio [density functional theory (BLYP) and Moller-Plesset perturbation theory (MP2)] computations utilizing standard basis sets, 6-31G* (optimizations) and 6-311+G* (single-point energy evaluations), agree with the experimental results implicating the involvement of the same radical cation intermediates in the activation processes. Isomeric radical cations formed from different precursors can equilibrate with low barriers (2.0-11.7 kcal mol(-1)) and lead to common products. The computed and experimental adiabatic ionization potential of adamantane shows that activation with NO+BF4- is also likely to occur through the adamantyl radical cation. Hence, the bonds need not be attacked directly by the electrophile in the C-H or C-C activation of alkanes with relatively low ionization potentials.
