Heck Reactions of Aryl Chlorides Catalyzed by Ligand Free Palladium Salts

Abstract

Palladium acetate has been shown to be a highly active catalyst for Heck reactions of aryl chlorides even in the absence of organic ligands. Bromobenzene can efficiently be coupled in presence of negligible traces of Pd, resulting in the highest TON (4.7 9 10 7 ) and TOF (1.2 9 10 7 h -1 ) values that have ever been reported for this system up to now.

Increased Conversion in the Heck Reaction Under Irradiation with Light

“…Both heterogeneous (Pd(II)/Al 2 O 3 and Pd(II)/TiO 2 ) [21] and homogeneous (palladium(II) acetate, Pd(OAc) 2 ) [22] catalysts were used in reacting bromobenzene (BrPh) with styrene (140°C, 2 h, Scheme 2). Samples were irradiated with UV-vis light, and a control reaction was also performed in the absence of light.…”

Macrocyclic Palladium(II) Complexes in CC Coupling Reactions: Efficient Catalysis by Controlled Temporary Release of Active Species

“…This demonstrates the strong chelating ability of Ia, since even ultra-trace amounts of Pd have been shown to effectively catalyze the Heck reaction of bromobenzene and styrene. [31] The practically quantitative Heck reaction with 4-chloroanisole (as shown in Table 1, entry 14) also did not occur anymore, when 1 equivalent of Ia was present in the reaction mixture, thus changing the amount of released Pd away from the found optimum value (Table 8, …”

Carbon–carbon coupling reactions catalyzed by supported Pd porphyrins

“…Homogenous palladium catalysts used in Suzuki and Heck reactions cannot be recovered from reaction media . The use of heterogeneous catalysts in organic synthesis has now become a common practice, especially following the rapid development of combinatorial chemistry.…”

“…[4][5][6][7][8] Homogenous palladium catalysts used in Suzuki and Heck reactions cannot be recovered from reaction media. [9] The use of heterogeneous catalysts in organic synthesis has now become a common practice, [10,11] especially following the rapid development of combinatorial chemistry. Solid-supported palladium complexes having high activity and selectivity offer several significant practical advantages in synthetic and industrial chemistry; among those, the ease of separation of the catalyst from the desired reaction products and the ease of recovery and reuse of the catalyst are most important.…”