Gold-Catalyzed Tandem Cycloisomerization/Functionalization of in Situ Generated α-Oxo Gold Carbenes in Water

Abstract

A gold-catalyzed tandem cycloisomerization/functionalization of in situ generated α-oxo gold carbenes in water has been developed, which provides ready access to highly functionalized indole derivatives from o-alkynyl anilines and ynamides. Importantly, gold serves dual catalytic roles to mediate both the cycloisomerization of o-alkynyl anilines and the intermolecular oxidation of ynamides at the same time, thus providing a new type of concurrent tandem catalysis. The use of readily available starting materials, a simple procedure, and mild reaction conditions are other notable features of this method.

Gold(I)-Catalyzed Activation of Alkynes for the Construction of Molecular Complexity

“… 424 A gold(I)-catalyzed tandem cycloisomerization/intermolecular trapping of an in situ generated α-oxo gold(I) carbene involving this transformation has been described to form functionalized indoles 477 from o -alkynyl anilines and ynamides (Scheme 157 ). 425 In this transformation, gold(I) serves dual catalytic roles to mediate both the cycloisomerization of o -alkynyl anilines and the intermolecular oxidation of ynamides.…”

Ring strain strategy for the control of regioselectivity. Gold-catalyzed anti-Markovnikov cycloisomerization initiated tandem reactions of alkynes

“…In summary, by utilizing the steric strain in ring formation to achieve the control of regioselectivity, a variety of gold-catalyzed anti-Markovnikov cycloisomerization-initiated tandem reactions have been developed, providing a facile and efficient way for the construction of various synthetically useful heterocycles, especially the optically active N-heterocycles by combining the chiral tert-butylsulfinimine chemistry and gold catalysis [65][66][67][68][69][70][71][72][73][74][75]. In our opinion, this study will continue to be a very exciting area for the expedient synthesis of valuable heterocycles [76].…”

A Gold Carbene Manifold to Prepare Fused γ‐Lactams by Oxidative Cyclisation of Ynamides

“…Formation of the oxindole 3 l is noteworthy as electron‐donating ynamide substituents such as the p ‐methoxybenzene group were either not tolerated or not assessed in diverse ynamide oxidation processes (Scheme ) ,,,. Steric bulk at the ortho ‐positions of both substituents can also be accommodated ( 3 f / k ).…”