Gold‐Catalyzed Allyl–Allyl Coupling

Abstract

Goldringe: Kationische Gold(I)‐Komplexe katalysieren die intramolekulare Allyl‐Allyl‐Kupplung von Allylacetaten mit Allylstannanen mit ausgezeichneter Stereoselektivität (siehe Schema). Der Reaktionsmechanismus unterscheidet sich markant von dem der palladiumkatalysierten Reaktion.

Evolution of Propargyl Ethers into Allylgold Cations in the Cyclization of Enynes

“…[20] Benzyl ether 16 d gave 22 b and 23 b in a 3:1 ratio, whereas 16 e led to 23 c as the major product. These results are consistent with a mechanism in which the intermediate allyl cation in 24 abstracts a hydride from the ArCH 2 O group to form a h 1 -allyl-gold(I) 25, [21] which reacts at C1 or C3 with the oxonium cation to give 22 a-c or 23 a-c, respectively. [20c] A related 1,6-shift of a methoxy group was found in the gold-catalyzed cyclization of 1,7-enynes 26 a-c (Scheme 5).…”

Metal–Arene Interactions in Dialkylbiarylphosphane Complexes of Copper, Silver, and Gold

“…[18] Stable crystalline complexes 2 a,b with an acetonitrile ligand are highly active for nucleophilic additions, [18,19] skeletal rearrangement [20] and intramolecular cyclopropanation [21] of enynes, and other reactions. [1,[22][23][24][25] These cationic complexes make catalytic transformations possible under silver-free conditions, which is im-Keywords: arene ligands · copper · gold · phosphanes · silver Abstract: Dialkylbiphenylphosphane-Au I complexes exhibit only weak metalarene interactions with the covering arene ring. However, the contacts in isoleptic Ag I and Cu I complexes are shorter than the limiting values of 3.03 (Ag I ) and 2.83 (Cu I ).…”

Gold‐Catalyzed Allylation of Aryl Boronic Acids: Accessing Cross‐Coupling Reactivity with Gold

“…[1] Despite the rapid pace of recent developments, the majority of gold-catalyzed processes rely on a select few reaction manifolds: 1) Lewis acid catalysis, 2) p-activation, and 3) the generation of carbenoid intermediates (Scheme 1 A). [2] While these modes of reactivity have yielded important catalytic methodologies of broad scope and synthetic utility, [3] they are typified by catalytic cycles wherein gold maintains a +1 oxidation state, in stark contrast to the 2electron redox cycles characteristic of late transition metal catalysis. [4] Indeed, access to Au III intermediates under catalytic conditions typically requires strong F + or I 3+ oxidants.…”