Recent Advances in Palladium‐Catalyzed Cross‐Coupling Reactions at ppm to ppb Molar Catalyst Loadings

Abstract

We review here new developments in decreasing the catalyst loadings in palladium-catalyzed C-C bond-formation reactions to mol ppm or mol ppb levels.T his decreasest he cost of the catalyst and the toxicity of the reactions ystem, making the reactionm ore attractive to industry.T he Heck reaction, Sonogashira reaction, Suzuki-Miyaurac rosscoupling reaction, other cross-coupling reactions,a nd allylic arylation reactions are separately discussedt o show clearly the progress made in each type of reaction. Apart from the catalyst loading, the other parameters of the reaction( temperature,s olvent, etc.) are brieflyd iscussed to illustrate the shift toward greenerc onditions.F or most reactions,t his shift is underway or wella dvanced, andc atalyst loadings have been decreasedt ob elow 1mol ppm. An abundance of catalytic systems are now available,a nd it is sometimes difficult to identify the best one,b ecause the substratese xamined can vary widely from publication to publication.I nt he future,e mphasis should be placed on the studyingt he full scope of the reaction at mol ppm catalyst loadings,r athert han examining af ew examples at these levels during the reaction-optimization process.1I ntroduction 2M izoroki-Heck Coupling 3S onogashira Coupling 4S uzuki-MiyauraCross-Coupling 5O ther Cross-Coupling Reactions 6A llylic Arylation 7C onclusions

Carbonylative Suzuki coupling reactions catalyzed by ONO pincer–type Pd(II) complexes using chloroform as a carbon monoxide surrogate

“…The FT-IR spectra of Schiff base ligands HL [1][2][3] and their corresponding palladium(II) complexes 1, 2, and 3 are presented in Figures S1-S3, respectively. The FT-IR spectra of the ligands displayed broad bands in the range of 3369-3440 cm −1 attributed to ν OH and bands at 3212-3264 cm −1 due to ν NH, respectively.…”

“…[1] Development of efficient methods for the C-C bond formation is one of the enduring research theme in organic chemistry. [2][3][4] Transition metal-catalyzed carbonylative Suzuki cross-coupling reaction is one of the powerful methods to generate C-C bonds which are an integral part of structural skeleton of a wide variety of natural products, pharmaceutical drugs, agrochemicals, fine chemicals, and organic functional materials [5][6][7][8][9][10] (Figure 1).…”

Catalytic Performance of Nanoporous Metal Skeleton Catalysts for Molecular Transformations

“…The Suzuki-Miyaura cross-coupling of aryl halides with arylboron compounds catalyzed by Pd is one of the most efficient transformations fort he synthesis of av ariety of biarylso rs ubstituted aromatic compounds. [48] Except for the numerouss tudies on homogenous Pd catalysis, the heterogeneousc atalysis using Pd nanoparticles is considered to be an effi-cient and green process, [49] but it often suffers from agglomeration-induced deactivation andc onsiderable Pd leachingp roblems. Tanaka et al reportedt hat PdNPore prepared from metallic glass exhibited high catalytic activity and reusability for the Suzuki-Miyaura coupling of aryliodides with arylboronic acids (Scheme 27).…”

Structural, Luminescent and Thermal Properties of Heteronuclear PdII–LnIII–PdII Complexes of Hexadentate N2O4 Schiff Base Ligand

“…The studies on palladium complexes are mainly focused on their catalytic activity [1,2,3]. Pd is widely applied in fuel cells, electronics and the automobile industry, as well as in dental and jewelry alloys.…”