Journal of the American Chemical Society, Vol.117, No.46, 11434-11440, 1995
9-(Diisopropylamino)-9-Azabicyclo(3.3.1)Nonane and Tetraisopropylhydrazine - Isolable Radical Cations from Hydrazines with Nearly Perpendicular Lone Pairs
Cuprous iodide catalyzes the addition of isopropyl Grignard reagent to triisopropyldiazenium cation (6) to give tetraisopropylhydrazine (3), a reaction which produces mostly the hydride transfer and deprotonation products of 6 in its absence. 9-(Dusopropylamino)-9-azabicyclo[3.3.1]nonane (2), its 3-keto analogue (4), and 3 each give isolable radical cations. Crystal structures are reported for 2, 2(+)NO(3)(-),3(+)OTs(-)CH(3)CN, and 4. 2(+) has its isopropyl groups in different rotamers, and 3(+) is nearly isostructural with tetraisopropylethylene (11), with each isopropyl methyne hydrogen roughly bisecting the C(Me(2)) unit of an adjacent isopropyl group. The first dynamic NMR experiments reported on radicals demonstrate that 2(+) occupies the same conformation in solution as in the crystal, and allow rough estimation of the barriers for isopropyl group interconversion in 2(+) and 3(+) at similar to 11 kcal/mol. Cyclic voltammetry and photoelectron spectroscopic data are reported for 2 and 3.