Practical Cross-Coupling between O-Based Electrophiles and Aryl Bromides via Ni Catalysis

Abstract

Cross-coupling of various O-based electrophiles with aryl bromides was developed through Ni-catalyzed C-O activation in the presence of magnesium. Beside carboxylates, carbamates, and ethers, phenols exhibited excellent reactivity under modified conditions. This chemistry was featured as a simple and environmentally benign process with low catalyst loading and easy manipulations. The method exhibited broad substrate scopes.

Biaryl Construction Based on Nickel-Catalyzed C–O Bond Activation

“…Our group reported the Ni-catalyzed reductive crosscoupling of aryl esters 220 with aryl bromides 221 in 2016. 66…”

Synthesis of Biaryls via Decarbonylative Nickel-Catalyzed Suzuki–Miyaura Cross-Coupling of Aryl Anhydrides

“…1 2-(4-Methoxyphenyl)naphthalene (3a). 19 White solid (41 mg, 88%); mp 116.8−117.3 °C. EtOAc/petroleum ether = 1:80.…”

“…1 2-(3,5-Dimethoxyphenyl)naphthalene (3b). 19 Yellow oil (43 mg, 81%). EtOAc/petroleum ether = 1:40.…”

Chromium-Catalyzed, Regioselective Cross-Coupling of C–O Bonds by Using Organic Bromides as Reactants

“…Shi and co-workers achieved a nickel-catalyzed crosscoupling of C-O bonds with aryl bromides in the presence of metallic magnesium with t-BuI as a key ligand (Scheme 1a). 20 We assumed that the treatment of an organic bromide with metallic magnesium in THF might permit the formation of the corresponding Grignard reagent in situ; 21 this might play a dual role by serving as a reductant to reduce the chromium salt and as a partner to couple with the C-O bond. Our previous studies suggested that an imino scaffold that is adjacent to a C-O bond of an aryl methyl ether is indispensable in assisting chelation of chromium in the activation of the C-O bond.…”