Air-stable trialkylphosphonium salts: Simple, practical, and versatile replacements for air-sensitive trialkylphosphines. Applications in stoichiometric and catalytic processes

[GRAPHICS] Trialkylphosphines furnish unusual, sometimes unique, reactivity in a range of transformations. Unfortunately, their utility is compromised by their sensitivity to oxidation, We have examined a simple but powerful strategy for addressing this problem: convert air-sensitive trialkylphosphines into air-stable phosphonium salts via protonation on phosphorus. These robust salts serve as direct replacements for the corresponding phosphines (simple deprotonation under the reaction conditions by a Bronsted base liberates the trialkylphosphine) in a diverse set of applications.