Gold(I)/Gold(III) Catalysis that Merges Oxidative Addition and π‐Alkene Activation

Abstract

Heteroarylation of alkenes with aryl iodides was efficiently achieved with a (MeDalphos)AuCl complex through AuI/AuIII catalysis. The possibility to combine oxidative addition of aryl iodides and π‐activation of alkenes at gold is demonstrated for the first time. The reaction is robust and general (>30 examples including internal alkenes, 5‐, 6‐, and 7‐membered rings). It is regioselective and leads exclusively to trans addition products. The (P,N) gold complex is most efficient with electron‐rich aryl substrates, which are troublesome with alternative photoredox/oxidative approaches. In addition, it provides a very unusual switch in regioselectivity from 5‐exo to 6‐endo cyclization between the Z and E isomers of internal alkenols.

Theoretical Study on NHC−Ag(I)/Au(I) Catalyzed Mobius Versus Wagner‐Meerwein Rearrangements of 2‐Methyl‐N‐methoxyaniline

“…As shown in the Figure S7, there is a weak interaction between Ag and N/O atoms in intermediate 2 (NÀ Ag = 2.24 Å, OÀ Ag = 2.13 Å), indicating the Ag(I) properties (prefers 2 i). However, intermediate 2' is an obvious Au(III) complex with shorter NÀ Au and OÀ Au distances via oxidative addition of Au(I) [18] (prefers 2'). These facts suggest that the covalent bonds can be converted into coordinate bonds between the lone pair orbitals of the N/O atom on the metal centers.…”

Fundamental Basis for Implementing Oxidant‐Free Au(I)/Au(III) Catalysis

“…Therefore, the same group took advantage of the great performance of MeDalphos ligand to develop the oxy-and aminoarylation of alkenols and alkenamines by means of Au(I)/Au(III) catalysis that combines oxidative addition of aryl iodides with π-activation of olefins (Figure 13d). [72] This strategy proved suitable to access products with 5-, 6-and 7-membered rings and electron-rich aryl substrates reacted readily. Likewise, the group of Patil also employed the MeDalphos ligand to synthesize 1,2-oxy-and 1,2aminoarylation products from the coupling of aryl iodides with alkenes.…”

“…Further, Bourissou and coworkers had already demonstrated the ability of MeDalphos ligand to stabilize gold(I) π‐complexes, [71] besides its capability to promote Au(I)/Au(III) two‐electron redox transformations. Therefore, the same group took advantage of the great performance of MeDalphos ligand to develop the oxy‐ and aminoarylation of alkenols and alkenamines by means of Au(I)/Au(III) catalysis that combines oxidative addition of aryl iodides with π‐activation of olefins (Figure 13d) [72] . This strategy proved suitable to access products with 5‐, 6‐ and 7‐membered rings and electron‐rich aryl substrates reacted readily.…”

A Systematic Study of the Effects of Complex Structure on Aryl Iodide Oxidative Addition at Bipyridyl‐Ligated Gold(I) Centers

“…[4] These fundamental studies have led to the use of the Au I /Au III redox couple in an emerging family of catalytic and stoichiometric cross-couplings. [3,[10][11][12][13] In particular,MeDalPhos has been employed in Au-catalyzed CÀHa rylations, [3] C(sp 2 )ÀNc ross-couplings [10] and alkene functionalizations. [11] With 2,2'-bipyridyl ligands, our group demonstrated all elementary steps of aN egishitype cross-coupling at aA ucenter.…”

“…[3,[10][11][12][13] In particular,MeDalPhos has been employed in Au-catalyzed CÀHa rylations, [3] C(sp 2 )ÀNc ross-couplings [10] and alkene functionalizations. [11] With 2,2'-bipyridyl ligands, our group demonstrated all elementary steps of aN egishitype cross-coupling at aA ucenter. [4] An attractive feature of these processes is the rate enhancement of oxidative addition for C(sp 2 ) À Xs ubstrates bearing electron-donating substituents-this is the reverse of the trend observed with L n Pd-(0).…”