Accessing Frustrated Lewis Pair Chemistry from a Spectroscopically Stable and Classical Lewis Acid-Base Adduct.

B(C6 F5 )3 and P(MeNCH2 CH2 )3 N form a classical Lewis adduct, (C6 F5 )3 BP(MeNCH2 CH2 )3 N. Although (C6 F5 )3 BP(MeNCH2 CH2 )3 N does not exhibit spectroscopic evidence of dissociation into its constituent acid and base, products of frustrated Lewis pair (FLP) addition reactions are seen with PhNCO, PhCH2 N3 , PhNSO, and CO2 . Computational studies show that thermal access to the dissociated acid and base permits FLP reactivity to proceed. These results demonstrate that FLP reactivity extends across the entire continuum of equilibria governing Lewis acid-base adducts.