Hiyama Cross-Coupling of Arenediazonium Salts under Mild Reaction Conditions

Abstract

Palladium acetate [Pd(OAc)(2)]-catalyzed Hiyama cross-coupling of arenediazonium salts with organosilanes was found to generate biaryl products in high yields in alcoholic solutions. The simple and efficient protocol does not require any bases, ligands, or air/moisture. The transformation can tolerate either electron-donating or electron-withdrawing functional groups. Theoretical studies show that the transmetalation is the rate-limiting step for the cross-coupling reaction and both acetate and tetrafluoroborate anions may be involved in the direct reaction with the silicon atom.

Carbonylative Hiyama coupling of aryl halides with arylsilanes under balloon pressure of CO

“…This poor yield may be due to steric hindrance. The thienyl and pyridinyl group survived well under the standard conditions, giving the corresponding products in moderate yields (Table 4, entries [13][14]. Importantly, structurally challenging nitrogen heterocyclic moiety in a number of bioactive natural products, such as oxazole and pyrimidine derivatives, were also coped with this conditions (Table 4, entries 15-16).…”

Palladium-catalyzed denitrogenative Hiyama cross-coupling with arylhydrazines under air

“…Pd(OAc) 2 , PdCl 2 , PdBr 2 and PdI 2 were somewhat effective, giving a 78%, 73%, 71% and 74% yield of 4-methyl-1,1'-biphenyl (entries 4-7). Other palladium(II) compounds with phosphine ligands led to higher amounts of desired products (entries [8][9][10][11], and the denitrogenative coupling was inhabited with Pd (0) catalysts (entries 12-13). To our delight, Pd(CH 3 CN) 2 Cl 2 served as a catalyst to afford the desired biaryl products in 89% yield (entry 14).…”

“…In 2011, Qi and coworkers reported a practical carbon-nitrogen bond cleavage procedure for the Hiyama cross-coupling reactions using arenediazonium salts as the electrophilic reagents. 10 Notably, aryl diazonium salts are required to be freshly prepared and need to be kept in storage under zero degree. 11…”

Computational Studies of Synthetically Relevant Homogeneous Organometallic Catalysis Involving Ni, Pd, Ir, and Rh: An Overview of Commonly Employed DFT Methods and Mechanistic Insights

“…A computational study by Qi and co-workers suggested that in addition to the acetate anion, also a weakly coordinating tetrafluoroborate anion might coordinate the silane and assist in the transmetallation step of Hiyama coupling. 209 3.1.6. Negishi Coupling.…”