Recent Advances in Copper-mediated Direct Biaryl Coupling

Abstract

Copper salts and complexes have recently received significant attention as less expensive, abundant, and unique alternatives to noble transition-metal catalysts such as palladium, rhodium, and ruthenium, in the research field of C–H activation. This highlight review focuses on recent advances in copper-mediated biaryl coupling via aromatic C–H cleavage, and the scope and limitations are briefly summarized.

Application of Palladium-Catalyzed C(sp2)–H Bond Arylation to the Synthesis of Polycyclic (Hetero)Aromatics

“…7,13,14 Recently, environmental concerns have significantly affected the way to practice organic synthesis by developing newly sustainable transformations. [15][16][17][18][19][20][21] Transition metal-catalyzed direct C-H bond functionalizations adopts this approach owing the use of non prefunctionalized substrates and minimizing the chemical wastes. Among diverse protocols, Pd-catalyzed intra-and/or intermolecular C-H bond arylation has recently attracted a lot of attention for the synthesis of decorated π-conjugated polycycles including some unprecedented structures.…”

Cobalt(III)‐Catalyzed CH/NO Functionalizations: Isohypsic Access to Isoquinolines

“…The CÀH/NÀOf unctionalization proceeded moste fficiently with AgSbF 6 and NaOAc as the additives (Table 1, entries [1][2][3][4][5][6][7][8][9][10]. This finding can be rationalized in terms of ac arboxylate-as- sisted [14] CÀHa ctivation by ac ationic cobalt(III) catalyst.…”

“…[2] Despite these undisputed advances, isohypsic alkyne annulationsw ere thus far only realized with costly 4d or 5d transition-metal catalysts. [4] Versatilec obalt catalysts have been applied for chemoselective CÀHt ransformations, [5] with notable progress being accomplished with cobalt(III) complexes as reported by Matsunaga/Kanai, [6] our group, [7] Glorius, [8] Ellman, [9] andC hang [10] among others. [4] Versatilec obalt catalysts have been applied for chemoselective CÀHt ransformations, [5] with notable progress being accomplished with cobalt(III) complexes as reported by Matsunaga/Kanai, [6] our group, [7] Glorius, [8] Ellman, [9] andC hang [10] among others.…”

Photocatalytic/Cu‐Promoted C−H Activations: Visible‐light‐Induced ortho‐Selective Perfluoroalkylation of Benzamides

“…Since Daugulis’ pioneering work, 8‐aminoquinoline has emerged as one of the most powerful and versatile directing groups for transition‐metal catalyzed or ‐promoted functionalization of C−H bonds, as exemplified by the huge number of recent publications in this area . Cu‐,– Pd‐, Ni‐, Co‐,– and Fe‐catalyzed or ‐mediated chelation‐assisted C−H bond activations to construct C−C and C−X bonds (X=S, O, N, F) [Eq. (1)] with the aid of an 8‐aminoquinoline directing group have been developed by the groups of Daugulis, Hirano, and Miura,– Ge, Kuninobu and Kanai,, Stahl, Chatani,,– and others ––.…”