Mingzhong Cai

Bio: Mingzhong Cai is an academic researcher from Jiangxi Normal University. The author has contributed to research in topics: Catalysis & Palladium. The author has an hindex of 30, co-authored 436 publications receiving 3363 citations. Previous affiliations of Mingzhong Cai include Hangzhou University.

Recyclable heterogeneous palladium-catalyzed carbon–carbon coupling polycondensations toward highly purified conjugated polymers

Abstract: Conjugated polymers are usually synthesized by homogeneous palladium complexes-catalyzed Heck, Suzuki, and Stille coupling reactions, which suffer from the non- recyclability of expensive palladium catalysts and palladium contamination of the desired polymer due to palladium leaching. In order to overcome these drawbacks, a bidentate phosphino-modified magnetic nanoparticles-anchored palladium complex (PdCl2-Fe3O4@SiO2-2P) as a clean and efficient heterogeneous catalyst for the carbon–carbon coupling polycondensations was developed in present work. The PdCl2-Fe3O4@SiO2-2P catalyst exhibited an enhanced catalytic activity for Heck, Suzuki, and Stille coupling polymerizations, as compared with the most commonly used homogeneous Pd(PPh3)4. Moreover, this heterogeneous palladium catalyst showed advantage of much less palladium impurity (below 13 ppm) in the isolated polymers. Importantly, PdCl2-Fe3O4@SiO2-2P can facilely be separated from the reaction products and recovered by using an external magnetic field, and recycled at least eight times with almost consistent catalytic activity.

Carbon-Carbon Coupling Reactions Catalyzed by Heterogeneous Palladium Catalysts

Abstract: 4.4. Pd on Modified Silica 159 4.5. Pd on Clay and Other Inorganic Materials 159 5. Stille, Fukuyama, and Negishi Reactions 159 5.1. Stille Reactions 159 5.1.1. Pd on Carbon (Pd/C) 159 5.1.2. Palladium on KF/Al2O3 159 5.1.3. Pd on Modified Silica (SiO2/TEG/Pd) 159 5.2. Fukuyama Reactions 159 5.2.1. Pd on Carbon (Pd/C) 159 5.2.2. Pd(OH)2 on Carbon (Perlman’s Catalyst) 160 5.3. Pd/C-Catalyzed Negishi Reactions 160 6. Ullmann-Type Coupling Reactions 161 6.1. Pd/C-Catalyzed Aryl−Aryl Coupling 161 6.2. Pd/C-Catalyzed Homocoupling of Vinyl Halides 162

On the Nature of the Active Species in Palladium Catalyzed Mizoroki–Heck and Suzuki–Miyaura Couplings – Homogeneous or Heterogeneous Catalysis, A Critical Review

Abstract: A wide array of forms of palladium has been utilized as precatalysts for Heck and Suzuki coupling reactions over the last 15 years. Historically, nearly every form of palladium used has been described as the active catalytic species. However, recent research has begun to shed light on the in situ transformations that many palladium precatalysts undergo during and before the catalytic reaction, and there are now many suggestions in the literature that narrow the scope of types of palladium that may be considered true “catalysts” in these coupling reactions. In this work, for each type of precatalyst, the recent literature is summarized and the type(s) of palladium that are proposed to be truly active are enumerated. All forms of palladium, including discrete soluble palladium complexes, solid-supported metal ligand complexes, supported palladium nano- and macroparticles, soluble palladium nanoparticles, soluble ligand-free palladium, and palladium-exchanged oxides are considered and reviewed here. A considerable focus is placed on solid precatalysts and on evidence for and against catalysis by solid surfaces vs. soluble species when starting with various precatalysts. The review closes with a critical overview of various control experiments or tests that have been used by authors to assess the homogeneity or heterogeneity of catalyst systems.

Recent advances in Sonogashira reactions

Abstract: The coupling of aryl or vinyl halides with terminal acetylenes catalysed by palladium and other transition metals, commonly termed as Sonogashira cross-coupling reaction, is one of the most important and widely used sp2–sp carbon–carbon bond formation reactions in organic synthesis, frequently employed in the synthesis of natural products, biologically active molecules, heterocycles, molecular electronics, dendrimers and conjugated polymers or nanostructures. This critical review focuses on developments in the Sonogashira reaction achieved in recent years concerning catalysts, reaction conditions and substrates (352 references).

Palladium-catalyzed carbonylation reactions of aryl halides and related compounds.

Abstract: Palladium-catalyzed carbonylation reactions of aromatic halides in the presence of various nucleophiles have undergone rapid development since the pioneering work of Heck and co-workers in 1974, such that nowadays a plethora of palladium catalysts are available for different carbonylative transformations. The carboxylic acid derivatives, aldehydes, and ketones prepared in this way are important intermediates in the manufacture of dyes, pharmaceuticals, agrochemicals, and other industrial products. In this Review, the recent academic developments in this area and the first industrial processes are summarized.