Phosphine-scavenging cationic gold(I) complexes: alternative applications of gold cocatalysis in fundamental palladium-catalyzed cross-couplings

We have demonstrated that air-stable cationic gold(I) cocatalysts have the capacity to enhance the efficiency of palladium-catalyzed cross-couplings. Specifically, we determined that a 1:1 [Pd{P( t -Bu) 3 } 2 ]/[Au{P( t -Bu) 3 }(NTf 2 )] system provides superior reactivity relative to [Pd{P( t -Bu) 3 } 2 ], across SuzukiMiyaura, Stille, and MizorokiHeck reactions performed under mild conditions. Our results are consistent with cationic gold(I) species serving primarily as phosphine scavengers in this chemistry, as recently predicted by density functional theory (DFT).