Bis(tri-tert-butylphosphine)palladium(0) [Pd(t-Bu3P)2

Abstract

The catalyst bis(tri-tert-butylphosphine)palladium(0) [Pd(t-Bu3P)2, 1, CAS: 53199-31-8] is a colorless, air-sensitive solid. It must be manipulated in a glove box or under inert gas. [Pd(t-Bu3P)2] (1) contains bulky, electron-rich tertiary phosphine ligands [t-Bu3P]. In a palladium-catalyzed cross-coupling reaction, they promote the oxidative addition as they can stabilize higher oxidation states. Reductive elimination is also facilitated because of the bulky ligands. Thus 1 has been shown to be superior in transition-metal-catalyzed cross-coupling reactions compared to the classical [Pd(Ph3P)4] catalyst. [Pd(t-Bu3P)2] is not only efficient for typical cross-coupling reactions, such as Stille, Negishi, Suzuki, Heck, Sonogashira, or Buchwald–Hartwig aminations, with electrophiles R-X (X = Cl, Br, I, OTf, SO2Cl and others), but also for cross-coupling of organolithium reagents,[1] alkenylgermanes,[2] alkali-metal silanolates,[3] triorgano-indium reagents[4] and others. Moreover, it has been used for arylations of hydro-siloxanes,[5] decarboxylative cross-coupling reactions,[6] carbonylations and amino-carbonylations,[7] carboiodinations,[8] C-H functionalizations,[9] cyanations,[10] methylenation of olefins[11] and annulation reactions.[12] In recent years, 1 has become one of the best new-generation catalysts and plays an important role in organic synthesis.