Bicyclo[1.1.1]pent-1-yl: A tertiary alkyl radical with enhanced reactivity

Article abstract of DOI:10.1016/0040-4039(96)01825-4

Absolute rate constants for reactions of bicyclo[1.1.1]pent-1-yl radicals with α-methylstyrene (1.4 x 10⁷ M^-1s^-1) and 1,4-cyclohexadiene (4.6 x 10⁵ M-¹s^-1) at 25°C were measured by laser flash photolysis. This bridgehead radical is more reactive than tert-butyl which we attribute to its high s-character and the absence of steric shielding of the radical center.