Cobalt-Catalyzed Cross-Coupling Reactions of Arylboronic Esters and Aryl Halides

Abstract

An efficient cobalt catalyst system for the Suzuki−Miyaura crosscoupling reaction of arylboronic esters and aryl halides has been identified. In the presence of cobalt(II)/terpyridine catalyst and potassium methoxide, a diverse array of (hetero)biaryls have been prepared in moderate to excellent yields.

Terpyridine-metal complexes: Applications in catalysis and supramolecular chemistry

“…Very recently, Teo reported the application of Co complexes in promoting Suzuki-Miyaura coupling reaction [26]. Various bidentate and tridentate ligands were tested and modified terpyridine gave the optimal results, which provided another example for the unique reactivity offered by this Pincer NNN ligand.…”

“…As a result, three pyridines adopt perfect coplanar conformation, allowing a good conjugation between the aromatic rings and metal cation. This feature makes tpy a potential "non-innocent" ligand, with the capability to stabilize the low valency metal, including nickel [14][15][16][17][18][19][20][21][22][23], iron [24,25], cobalt [26][27][28][29] and manganese [30,31] etc. Interesting catalytic reactivity has been obtained with these tpy-metal complexes targeting some challenging transformations, such as C-C unsaturated bond hydrofunctionalization and C-C bond formation.…”

“…Some promising examples were reported in the metal hydride chemistry including by tpy-Ru [69][70][71][72][73] and tpy-Rh [74][75][76] complexes/catalysts. More recently, tpy-Mn, tpy-Fe and tpy-Co complexes have been successfully identified for C-C multiple bond hydrofunctionalization and cross-coupling [24][25][26][27][28][29][30][31]. These recent successes triggered great excitement and enthusiasm in further exploring potential new reactivity of this unique terpyridine.…”

Tailoring of the Frontier Orbital Character in Co2+/3+ Complexes with Triarylamine Substituted Terpyridine Ligands

“…In particular, a value of Σ cis = 135.6°as found for 4 [Co 2+ (1) 2 ] 2+ by DFT is remarkable. For instance, cis-angle distortion of parent 4 [Co 2+ (tpy) 2 ] 2+ is substantially smaller if computed on the same level of theory (Σ cis = 121.6°, this work) and in the solid-state {[Co(tpy) 2 ](BF 4 ) 2 ; Σ cis = 120.0° [ 20] }. We note in passing that, very recently, high degrees of cis-angle distortion have been associated with enhanced cooperativity in Co 2+ -SCO compounds in the crystal.…”

“…Mass spectra were recorded with a Bruker micrOTOF-QIIa mass spectrometer operating in ESI mode (ESI = electrospray ionisation). 4 ] in acetonitrile, propylene carbonate and dichloromethane, respectively. [55,56,[80][81][82][83] The working electrode was prepared by polishing on a Buehler microcloth first with a 1 μm and then with a 1 / 4 μm diamond paste before every measurement.…”