Strong Metallophilic Interactions in the Palladium Arylation by Gold Aryls

Abstract

and the Junta de Castilla y León (VA281A11-2 and VA373A11-2) for financial support; CESGA for generous allocation of computational resources; and Dr. JosØ M. Aurrecoechea (Universidad del País Vasco) for discussions.Supporting information for this article is available on the WWW under http://dx.

A Theoretical DFT‐Based and Experimental Study of the Transmetalation Step in Au/Pd‐Mediated Cross‐Coupling Reactions

“…The overall thermodynamic data for the transmetalation step compared to the cis ‐complex [PdXPhL 2 ] ( cis ‐ 1 a , c ) is Δ G trans =+1.4 kcal mol −1 (X=Cl) and Δ G trans =−0.9 kcal mol −1 (X=I), respectively, is in accord with the thermodynamic results for the transmetalation reaction employing the chelate ligand on Pd (Table 2). Interestingly, the transmetalation thermodynamics are highly endergonic Δ G trans =+13.5 kcal mol −1 (X=Cl); Δ G trans =+10.2 kcal mol −1 (X=I) if compared with the trans ‐[PdXPhL 2 ] complex ( trans ‐ 1 a , c ), which is in good agreement with the experimental and theoretical results by Espinet et al 16a. studying the favored (exergonic) transmetalation from Pd to Au starting with [PdR 2 L 2 ].…”

Stille Coupling Involving Bulky Groups Feasible with Gold Cocatalyst

“…The aim of bimetallic catalysis is to take advantage of the specific behavior of each catalyst in new one‐pot synthetic routes. For the Au/Pd couple it is known that the Au/Pd transmetalation, a step which is hoped to connect the palladium and the gold catalytic cycles, is kinetically feasible,2, 3 even for fairly bulky groups 4. However, so far only a few Au/Pd bimetallic catalyzed processes have been reported, including the Sonogashira‐like cross‐coupling,5 the carbometallation of alkynes,6 and processes combining cyclization with cross‐coupling steps 7.…”

“…The calculations were performed for the formation of (2‐methyl‐1‐(4‐(trifluoromethyl)phenyl)naphthalene (Table 2, entry 7) with the real molecules, except for the Sn( n Bu) 3 group, which was simplified to SnMe 3 . The transmetalation mechanisms from tin to palladium and from gold to palladium have been studied before for sterically nondemanding groups 3. 23 The transmetalation mechanism from tin to gold has not been studied so far, and is depicted in Scheme .…”

Synthesis of conjugated copolymers by combining different coupling reactions

“…As evidenced by the Lewis-Mayo plot, it is observed that the organogold monomer is built in more rapidly at the beginning of the polymerization, which can be explained by the favourable gold-palladium interactions. [31][32][33][34][35][36][37] As a consequence, a considerable amount of AuPtBu3Br is released into the reaction mixture at quite low conversions, which could possibly transmetallate with the stannylated butylthiophene monomer. 31 To investigate whether this reaction is actually occurring, AuPtBu3Br was synthesized by reacting AuPtBu3Cl with KBr in acetone.…”