NHC–Pd(II)–Im (NHC=N-heterocyclic carbene, Im=1-methylimidazole) complex catalyzed coupling reaction of arylboronic acids with carboxylic acid anhydrides in water

The crystal structure of 1,3-bis(2,6-diiso-propylphenyl)imidazol-2-ylidene)-dibromido-(1-methyl-1H-imidazole-κ1N)palladium(II) – ethyl acetate – water (1/1/1), C31H42Br2N4Pd

“…For instance, the synthesis of [1,3-bis(2,6-diisopropylphenyl)-1H-imidazol-2(3H)-ylidene]palladium complex, from easily available starting materials in a one-pot procedure was reported [1]. In addition, the applications of this complex have been fully investigated in Suzuki-Miyaura coupling [2,[11][12][13][14][15][16][17][18], C-N coupling [1,[19][20][21], α-arylation of carbonyl compounds [22][23][24][25][26], Hiyama coupling [27], Mizoroki-Heck reaction [28] and direct C-H bond functionalization of heteroaromatic compounds [29][30][31][32][33]. As its analogue, initial studies on the catalytic activity of the title complex showed that it is also an e cient catalyst in the C-N coupling between primary and secondary amines with aryl chlorides at very low catalyst loadings, implying that the anions on the complex may have no e ect on the catalytic activity.…”

Palladium-Catalyzed Cross-Coupling Reaction of Organoboron Compounds with Carboxylic Derivatives

“…2008 年 Xin 等 [45] 研究了于 水相中钯催化芳基硼酸与酸酐的交叉偶联反应, 该反应 只需使用 PdCl 2 催化剂和水与丙酮的混合溶剂即可在温 和条件下快速完成偶联反应. 钯催化剂与卡宾配体形成的络合物对多种金属试 剂的交叉偶联反应有良好的催化活性, 2011 年 Shao 等 [46] 从脯氨酸合成并鉴定了一个新的 NHC-Pd(II)-Im 配 合物(Scheme 17, complex 1), 以其为催化剂在弱碱条件 下可很好的完成芳基硼酸与酸酐的交叉偶联反应; 2012 年 Lu 等 [47] 报道了另一种 NHC-Pd(II)-Im 配合物(Scheme 前已述及在 Gooßen 所报道钯催化的芳基硼酸与酸 酐的偶联条件下特戊酸酐是不能反应的(Eq. 7), Gooßen 等 [48] 巧妙的利用这一特点发展了将羧酸与偶联惰性特 戊酸酐预反应再偶联的便捷方法, 从而实现了羧酸与有 机 硼 化 合 物 的 一 锅 法 高 效 偶 联 ; 在 随 后 的 研 究 中 Gooßen 等 [49] 2001 年 Gooßen 等 [51] 发现 N-benzoyloxysuccinimide 可与芳基硼酸发生交叉偶联反应后高收率的得到芳基 酮 产 物 .…”

Direct arylation of heteroaromatic compounds by Pd(OAc)2/tetrakis(N-benzimidazoliummethyl)benzene salt system

“…The intensive interest in NHCs has led to the parallel development of poly-NHCs [7][8][9][10][11][12][13] bearing bis-, tris-, tetra, and hexa ligands as well as mono-NHCs. 14,15 The use of poly-NHCs as chelating or bridging ligands provides more stability to the resulting metal complex and allows the synthesis of polynuclear complexes due to the robustness of metal-carbene interaction. [16][17][18][19] The investigation of poly-NHCs leads not only to the preparation of their metal complexes but also applications in catalysis (cross coupling reactions, 20,21 C-H activation and functionalization, 22 hydrogenation, 23 allylation 24 e.g.…”