Academic literature on the topic 'Cross-electrophile coupling'

AbstractNickel-catalyzed cross-electrophile coupling has become a powerful tool for the construction of molecules. These new bond-forming reactions bypass the requirement for the handling of organometallic reagents and are selectively orthogonal to classic cross couplings. This chapter provides a brief review of the achievements in this field. Selected methods for C—C coupling with a variety of reacting partners are presented. In addition to transformations involving a metal reductant, representative examples of nickel metallaphotocatalysis and electrochemical nickel catalysis are also discussed. Finally, expansion of this chemistry to the reactions of heavier group 14 electrophiles is described.

Aryl amines have received significant interest because these compounds widely exist in the structural backbones of ligands, pharmaceuticals, agrochemicals, natural products, and functional materials. In N-arylation reactions, several types of organic electrophile coupling partners such as (pseudo)halides (Ullmann-type and Buchwald–Hartwig couplings) and boronic acids (Chan–Lam coupling) are popular. The main synthetic methods for the preparation of these compounds involving N-arylation utilize aryl halides. Progress has been made with the coupling of arylating reagents which are less expensive than aryl halides, providing both a cost-effective and more efficient reaction route. For example, the process of C–H bond activation/functionalization, a step-efficient and atom-economical transformation, has emerged as a powerful strategy in C–N bond-forming reactions. Moreover, a transition-metal-free method for the N-arylation of amines using an aryne intermediate has been developed. This chapter focuses on recent advances in chemo- and regioselective N-arylation (either on one N-center or on the exocyclic N-site of the ring) or the selective arylation of amino alcohols without additional protection/deprotection using arylating reagents. This chapter provides an overview of arylating reagents for N-arylation reactions found in both basic and applied chemical research. The substrate scope, limitations, reaction mechanism, and chemoselectivity, as well as related control strategies of these reactions, are discussed. To the best of our knowledge, there has been no book about introducing arylating reagents to develop more efficient and environmentally friendly cross-coupling methods for the N-arylation of amines. We believe this critical review will provide necessary background information on the N-arylation of amines.

As part of the heterogeneous catalysis concept, nanoparticle catalysis is the advanced key technology to connect the divergence between classical chemical synthesis methods and environmentally benign sustainable synthesis processes. The demonstration of nanoparticle catalysts for the sustainable and mild synthesis of chemicals is a fast-growing area in catalysis. This chapter will focus on a series of catalytic systems for hydrogen transfer-type or so-called borrowing hydrogen reactions using supported metal catalysts to synthesize chemicals directly and will highlight a group of coupling reactions that generates C-O, C-C, C-N, and C-S bonds. These catalytic coupling reactions possess a general mechanistic aspect: dehydrogenation of poor electrophile alcohols/amines to activated electrophiles, condensation (self or cross or with different nucleophiles), and hydrogenation of condensate. The feasibility of these catalytic coupling reactions is abided with the proper catalyst design where supports are enriched with acidic, basic, or amphoteric properties that promote the condensation reactions, and metal nanoparticle sites are responsible for the hydrogen transfer from the alcohols or amines followed by the re-hydrogenation of the condensation product accordingly. Compared to the state-of-the-art homogeneous catalytic systems, these heterogeneous metal nanoparticle-catalyzed reactions possess catalytic reusability, catalytic efficiency, and sustainability advantages.

As part of the heterogeneous catalysis concept, nanoparticle catalysis is the advanced key technology to connect the divergence between classical chemical synthesis methods and environmentally benign sustainable synthesis processes. The demonstration of nanoparticle catalysts for the sustainable and mild synthesis of chemicals is a fast-growing area in catalysis. This chapter will focus on a series of catalytic systems for hydrogen transfer-type or so-called borrowing hydrogen reactions using supported metal catalysts to synthesize chemicals directly and will highlight a group of coupling reactions that generates C-O, C-C, C-N, and C-S bonds. These catalytic coupling reactions possess a general mechanistic aspect: dehydrogenation of poor electrophile alcohols/amines to activated electrophiles, condensation (self or cross or with different nucleophiles), and hydrogenation of condensate. The feasibility of these catalytic coupling reactions is abided with the proper catalyst design where supports are enriched with acidic, basic, or amphoteric properties that promote the condensation reactions, and metal nanoparticle sites are responsible for the hydrogen transfer from the alcohols or amines followed by the re-hydrogenation of the condensation product accordingly. Compared to the state-of-the-art homogeneous catalytic systems, these heterogeneous metal nanoparticle-catalyzed reactions possess catalytic reusability, catalytic efficiency, and sustainability advantages.