Transition‐Metal‐Catalyzed Direct Arylation of (Hetero)Arenes by CH Bond Cleavage

Abstract

The area of transition-metal-catalyzed direct arylation through cleavage of C-H bonds has undergone rapid development in recent years, and is becoming an increasingly viable alternative to traditional cross-coupling reactions with organometallic reagents. In particular, palladium and ruthenium catalysts have been described that enable the direct arylation of (hetero)arenes with challenging coupling partners--including electrophilic aryl chlorides and tosylates as well as simple arenes in cross-dehydrogenative arylations. Furthermore, less expensive copper, iron, and nickel complexes were recently shown to be effective for economically attractive direct arylations.

The Controlled Polymerization of Poly(cyclopentadithiophene)s and Their All-Conjugated Block Copolymers

“…[4][5][6][7] Herein, the transition metal catalyst forms a new C-C bond between two entities of which one carries a carbon-halogen bond, and the other one is, most frequently, an organometallic monomer system, although recent research also focuses on direct arylation where coupling takes place with a C-H bond instead of with an organometallic monomer. [8][9][10][11] The traditional transition metal catalyzed polymerization mechanisms generally proceed via a step-growth mechanism, and are still the most obvious choice for the synthesis of alternating copolymers. However, for other materials, it can be a great benefit to step away from these difficult-to-control polymerization mechanisms, towards a (controlled) chain-growth mechanism, in which polydispersities can be low, and molecular weights can be controlled.…”

Development of Batch and Flow Immobilized Catalytic Systems with High Catalytic Activity and Reusability

“…[167][168][169][170][171][172][173] The reaction of 12b with 2-methylthiophene (30) was carried out with SiNA-Pd (0.3 mol%) and CsOAc in DMF, then the reaction proceeded to give 2-methyl-5-phenylthiophene (31) in 80% yield. [174][175][176][177] The coupling of 12b with an indole (32) also proceeded under similar conditions to give the corresponding indole 33 in 63% yield.…”

Palladium(0)-Catalyzed Benzylic C(<i>sp</i>³)–H Functionalization for the Concise Synthesis of Heterocycles and Its Applications

“…[9][10][11][12][13][14][15][16][17][18][19][20] Under Pd catalysis, there are two main approaches for activating unreactive C(sp 2 )-H and C(sp 3 )-H bonds, including: i) an intramolecular approach; and ii) a directing group approach. A variety of different directing groups and reaction conditions involving Pd catalysts have been developed for extending the substrate scope of C-H functionalization reactions.…”