Gold-Catalyzed Heck Reaction

Abstract

Herein, we report a gold-catalyzed Heck reaction facilitated by the ligand-enabled Au(I)/Au(III) redox catalysis. The elementary organometallic steps such as migratory insertion and β-hydride elimination have been realized in the catalytic fashion for the first time in gold chemistry. The present methodology not only overcomes the limitations of previously known transition metalcatalyzed Heck reactions such as the requirement of specialized substrates and formation of a mixture of regioisomeric products as a result of the undesirable chain-walking process but also offers complementary regioselectivity as compared to other transition metal catalysis.

Hemilabile P,N-Ligand-Assisted Gold-Catalyzed Heck Reaction of Aryl and Styryl Iodides with Styrenes

“…On the basis of our experiments, mechanistic studies (see the Supporting Information) and literature reports, − we proposed the reaction mechanism of the gold-catalyzed Heck reaction with styrenes (Scheme ). First, cationic Au­(I) complex A was produced by the reaction of MeDalPhosAuCl with AgNTf 2 , and Au­(III) intermediate B was formed by the oxidative addition of A to aryl iodide 2 .…”

“…Recently, the Patil group reported a gold-catalyzed Heck reaction with aliphatic alkenes, which was facilitated by a hemilabile P,N-ligand-assisted Au­(I)/Au­(III) redox catalysis, and the elementary processes of migratory insertion and β-hydride elimination were realized in gold chemistry (Scheme b) . Compared with other transition-metal catalyses, this gold-catalyzed Heck reaction provides a complementary allylic product.…”

Site-Selective Arylation of Carboxamides from Unprotected Peptides

“…In recent years, homogeneous gold-catalyzed cross-coupling transformations − have exhibited excellent functional group tolerance and biocompatibility within aqueous reaction media. These unique features of gold catalysis offer a new opportunity for the late-stage modification (LSM) of peptides. , In 2019, Patil and coworkers have reported the first ligand-enabled gold-catalyzed arylation of a range of amines and amides with aromatic iodides .…”

Meerwein Arylation of Aryl(alkyl)idenemalononitriles and Diazonium Salts for the Synthesis of 2-(Aryl(alkyl)/arylmethylene)malononitrile Derivatives

“…The formation of C–C (sp 2 –sp 2 ) arylations is always the theme of organic synthesis and is often a key step in the synthesis of natural products, drugs, or functional materials. Although a variety of famous cross-coupling reactions, such as Heck, Suzuki, Negishi, Kumada, and Stille reactions, have been well established for the formation of C–C bonds, the principal drawbacks of these reactions could be found as follows: requirement of precious metal catalysts, difficulty in obtaining substrates, and harsh reaction conditions (such as oxygen-free and anhydrous conditions), often in combination with specific ligands and additives. Meerwein arylation was originally reported by Hans Meerwein in 1939, and was proven to be a versatile approach for C–C bond formation reactions, particularly in the functionalization of alkenes.…”