5.4. Miscellaneous Examples 2295 5.4.1. Couplings with Other Catalysts 2295 5.4.2. The Use of Other Boron Reagents 2295 5.4.3. Related Coupling Reactions 2296 5.5. Summary 2297 6. Sonogashira Coupling 2297 6.1. Couplings with Pd Particles 2297 6.2. Studies with Immobilized Palladium Complexes 2299 6.3. Miscellaneous Examples 2301 6.4. Carbonylative Sonogashira Couplings 2302 6.5. Summary 2302 7. Stille Couplings 2302 7.1. Stille Coupling 2302 7.2. Carbonylative Stille Coupling 2304 7.3. Summary 2304 8. Miscellaneous Cross-Coupling Reactions 2304 9. Allylations 2305 9.1. Tsuji-Trost Allylation 2305 9.2. Allylation of Boron Reagents 2306 10. Homocouplings 2307 10.1. Summary 2308 11. C-C Couplings in Continuous Systems 2308 12. Conclusions and Outlook 2311 Author Information 2314 Biography 2314 References 2314

Efficient, selective, and recyclable palladium catalysts in carbon-carbon coupling reactions.

Fast-growing field of magnetically recyclable nanocatalysts.

Many boronic acids, including 2-heterocyclic, vinyl, and cyclopropyl derivatives, are inherently unstable, which can limit their benchtop storage and/or efficient cross-coupling. We herein report the first general solution to this problem: in situ slow release of unstable boronic acids from the corresponding air-stable MIDA boronates. This remarkably general approach has transformed all three classes of these unstable boronic acids into shelf-stable and highly effective building blocks for cross-coupling with a wide range of aryl and heteroaryl chlorides.

A general solution for unstable boronic acids: Slow-release cross-coupling from air-stable MIDA boronates

Recent advancements and challenges of palladiumII-catalyzed oxidation reactions with molecular oxygen as the sole oxidant

Graphene has been successfully modified with palladium nanoparticles in a facile manner by reducing palladium acetate [Pd(OAc)2] in the present of sodium dodecyl sulfate (SDS), which is used as both surfactant and the reducing agent. The palladium nanoparticle–graphene hybrids (Pd–graphene hybrids) are characterized by highresolution transmission electron microscopy, atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and energy dispersive X-ray spectroscopy. We demonstrate that the Pd–graphene hybrids can act as an efficient catalyst for the Suzuki reaction under aqueous and aerobic conditions, with the reaction reaching completion in as little as 5 min. The influence of the preparation conditions on the catalytic activities of the hybrids is also investigated.

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Palladium Nanoparticle-Graphene Hybrids as Active Catalysts for the Suzuki Reaction

A highly efficient palladium acetate-catalyzed ligand-free Suzuki reaction in aqueous phase was developed in short reaction times (0.5−1 h) at 35 °C in air. The key for such a successful catalytic system was the use of a suitable amount of cosolvents in the aqueous phase. The method could be extended to the consecutive multi-Suzuki coupling, and polyaryls were prepared in a single one-pot step in high selectivity and excellent yield under mild reaction conditions (60 °C).

Synthesis of Biaryls and Polyaryls by Ligand-Free Suzuki Reaction in Aqueous Phase

The palladium acetate-catalyzed coupling reaction of aryl boronic acid with carboxylic anhydride or acyl chloride was carried out smoothly in water in the presence of poly(ethylene glycol) (PEG) or 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) to give high yields of ketones without the use of phosphine ligands. The Pd(OAc)2−H2O−[bmim][PF6] catalytic system can be recovered and reused eight times with high efficiency for both carboxylic anhydride and acyl chloride.

Phosphine-free cross-coupling reaction of arylboronic acids with carboxylic anhydrides or acyl chlorides in aqueous media.

The homocoupling reaction of the arylboronic acids proceeded smoothly in a mixture of water and ionic liquids in the presence of ethyl bromoacetate ester using Pd(OAc)2 as catalyst in high yield at 60 °C for 3 h. The separation of desired products was easily performed by extraction with diethyl ether and Pd(OAc)2–[bmim][PF6] (1-butyl-3-methylimidazolium hexafluorophosphate) can be reused eight times accompanied with only a slight decrease in activity.

The Pd(OAc)2-catalyzed homocoupling of arylboronic acids in water and ionic liquid

Synthesis of Biaryls and Polyaryls by Ligand‐Free Suzuki Reaction in Aqueous Phase.

The palladium(II) chloride catalyzed cross-coupling of arylboronic acids with carboxylic anhydrides or acyl chlorides in water in the presence of various surfactants is described. The inexpensive and industrially widely used sodium dodecyl sulfate (SDS) was found to be a good promoter of the coupling reaction and aryl ketones were obtained in good yields without the use of phosphine ligands. The reactions were unaffected by the presence of electron-releasing and electron-withdrawing substituents in both the arylboronic acids and carboxylic derivatives and a variety of aryl ketones were obtained under mild conditions in air.

Bingwei Xin

Papers

Synthesis of Biaryls and Polyaryls by Ligand-Free Suzuki Reaction in Aqueous Phase

Phosphine-free cross-coupling reaction of arylboronic acids with carboxylic anhydrides or acyl chlorides in aqueous media.

The Pd(OAc)2-catalyzed homocoupling of arylboronic acids in water and ionic liquid

Synthesis of Biaryls and Polyaryls by Ligand‐Free Suzuki Reaction in Aqueous Phase.

The Surfactant-Promoted Cross-Coupling Reactions of Arylboronic Acids with Carboxylic Anhydrides or Acyl Chlorides in Water