Tri(1-adamantyl)phosphine: Exceptional Catalytic Effects Enabled by the Synergy of Chemical Stability, Donicity, and Polarizability

Tri(1-adamantyl)phosphine, a simple yet long-absent homoleptic phosphine, has finally been prepared. The simplicity of this compound beguiles its exceptional properties. The electron-releasing character eclipses all other alkylphosphines. The phosphine geometry and overall size are also more compact than anticipated, which may occur as a result of dispersion forces. We believe the donicity, marked resistance towards cyclometallation or P−C bond scission, and also substantial polarizability engendered by the three diamondoid fragments together account for the phenomenal performance of Pd-PAd 3 catalysts during Suzuki–Miyaura coupling reactions. A correlation analysis is also described that provides support for polarizability as a potentially general influence on the properties of tertiary phosphines. 1 Introduction 2 Synthesis of Tri(1-adamantyl)phosphine 3 Reactions of Tri(1-adamantyl)phosphine Palladium Complexes 4 Electronic and Steric Properties of Tri(1-adamantyl)phosphine 5 Conclusion