Quantification of the Lewis Basicities and Nucleophilicities of 1,3,5‐Tris(dialkylamino)benzenes

Equilibrium constants for the formation of Wheland complexes from 1,3,5-tris(dialkylamino)benzenes and benzhydrylium ions (Ar2CH+) have been determined photometrically in dichloromethane solution at 20 °C. The Lewis basicity ring carbons increases series trimorpholinobenzene<tripiperidinobenzene<tripyrrolidinobenzene. complexes, which are formed with equilibrium 102<K/M−1<106 reactions triaminobenzenes carbenium ions, show temperature-dependent dynamic 1H NMR spectra, due to rapid reverse recombination different positions triaminobenzenes. Since rates too high be measured directly, they were calculated as product rate reactions, derived spectra. experimentally good agreement results DFT calculations using SMD solvent model. that all cases thermodynamically more stable than ammonium by attack amino group title compounds, explains exclusive controlled reactions. With nucleophilicity parameters range 10<N<15 comparable nucleophilic reactivities enamines, silyl ketene acetals well stabilized phosphonium sulfonium ylides.