Light‐Promoted Nickel Catalysis: Etherification of Aryl Electrophiles with Alcohols Catalyzed by a NiII‐Aryl Complex

A highly effective C?O coupling reaction of (hetero)aryl electrophiles with primary and secondary alcohols is reported. Catalyzed by a Ni^II‐aryl complex under long‐wave UV (390–395 nm) irradiation in the presence of a soluble amine base without any additional photosensitizer, the reaction enables the etherification of aryl bromides and aryl chlorides as well as sulfonates with a wide range of primary and secondary aliphatic alcohols, affording synthetically important ethers. Intramolecular C?O coupling is also possible. The reaction appears to proceed via a Ni^I–Ni^III catalytic cycle.     

Generation of Organozinc Reagents by Nickel Diazadiene Complex Catalyzed Zinc Insertion into Aryl Sulfonates

The generation of arylzinc reagents (ArZnX) by direct insertion of zinc into the C−X bond of ArX electrophiles has typically been restricted to iodides and bromides. The insertions of zinc dust into the C−O bonds of various aryl sulfonates (tosylates, mesylates, triflates, sulfamates), or into the C−X bonds of other moderate electrophiles (X=Cl, SMe) are catalyzed by a simple NiCl₂–1,4-diazadiene catalyst system, in which 1,4-diazadiene (DAD) stands for diacetyl diimines, phenanthroline, bipyridine and related ligands. Catalytic zincation in DMF or NMP solution at room temperature now provides arylzinc sulfonates, which undergo typical catalytic cross-coupling or electrophilic substitution reactions.     

Nickel‐Catalyzed Cross‐Coupling of Organolithium Reagents with (Hetero)Aryl Electrophiles

Nickel‐catalyzed selective cross‐coupling of aromatic electrophiles (bromides, chlorides, fluorides and methyl ethers) with organolithium reagents is presented. The use of a commercially available nickel N‐heterocyclic carbene (NHC) complex allows the reaction with a variety of (hetero)aryllithium compounds, including those prepared via metal‐halogen exchange or direct metallation, whereas a commercially available electron‐rich nickel‐bisphosphine complex smoothly converts alkyllithium species into the corresponding coupled product. These reactions proceed rapidly (1 h) under mild conditions (room temperature) while avoiding the undesired formation of reduced or homocoupled products.     

Highly Chemoselective Iridium Photoredox and Nickel Catalysis for the Cross‐Coupling of Primary Aryl Amines with Aryl Halides

A visible‐light‐promoted iridium photoredox and nickel dual‐catalyzed cross‐coupling procedure for the formation C?N bonds has been developed. With this method, various aryl amines were chemoselectively cross‐coupled with electronically and sterically diverse aryl iodides and bromides to forge the corresponding C?N bonds, which are of high interest to the pharmaceutical industries. Aryl iodides were found to be a more efficient electrophilic coupling partner. The coupling reactions were carried out at room temperature without the rigorous exclusion of molecular oxygen, thus making this newly developed Ir‐photoredox/Ni dual‐catalyzed procedure very mild and operationally simple.     

在吡啶溶剂中氯化镍催化的溴代芳烃自身偶联反应

Pyridine was used as a solvent for homocoupling of aryl bromides catalyzed by nickel chloride/triarylphosphinein the presence of zinc and recycled easily.Triphenylphosphine was the best ligand for nickel in this coupling reac-tion.     

Nickel‐Catalyzed Enantioselective CC Bond Formation through CO Cleavage in Aryl Esters

We report the first enantioselective C? C bond formation through C? O bond cleavage using aryl ester counterparts. This method is characterized by its wide substrate scope and results in the formation of quaternary stereogenic centers with high yields and asymmetric induction.     

Synthesis of Phenols: Organophotoredox/Nickel Dual Catalytic Hydroxylation of Aryl Halides with Water

A highly effective hydroxylation reaction of aryl halides with water under synergistic organophotoredox and nickel catalysis is reported. The OH group of the resulting phenols originates from water, following deprotonation facilitated by an intramolecular base group on the ligand. Significantly, aryl bromides as well as less reactive aryl chlorides served as effective substrates to afford phenols with a wide range of functional groups. Without the need for a strong inorganic base or an expensive noble‐metal catalyst, this process can be applied to the efficient preparation of diverse phenols and enables the hydroxylation of multifunctional pharmaceutically relevant aryl halides.     

Sulfonamidation of Aryl and Heteroaryl Halides through Photosensitized Nickel Catalysis

Herein we report a highly efficient method for nickel‐catalyzed C?N bond formation between sulfonamides and aryl electrophiles. This technology provides generic access to a broad range of N‐aryl and N‐heteroaryl sulfonamide motifs, which are widely represented in drug discovery. Initial mechanistic studies suggest an energy‐transfer mechanism wherein C?N bond reductive elimination occurs from a triplet excited Ni^II complex. Late‐stage sulfonamidation in the synthesis of a pharmacologically relevant structure is also demonstrated.     

CaY-zeolite Catalyzed Etherification and Alkylation of Substituted Benzyl Alcohols

Besides the great success in petroleum chemistry and related fields, the utilization of zeolites for selective organic synthesis has grown continuously in recent years1-3. The combination of acidic and shape selective properties of zeolites renders them p…     

Water Oxidation Catalyzed by a Dinuclear Cobalt–Polypyridine Complex

The dinuclear Co complex [(TPA)Co(μ‐OH)(μ‐O₂)Co(TPA)](ClO₄)₃ ( 1 , TPA=tris(2‐pyridylmethyl)amine) catalyzes the oxidation of water. In the presence of [Ru(bpy)₃]²⁺ and S₂O₈^2?, photoinduced oxygen evolution can be observed with a turnover frequency (TOF) of 1.4±0.1 mol(O₂) mol( 1 )^?1 s^?1 and a maximal turnover number (TON) of 58±5 mol(O₂) mol( 1 )^?1. The complex is shown to act as a molecular and homogeneous catalyst and a mechanism is proposed based on the combination of EPR data and light‐driven O₂ evolution kinetics.     

Biaryl and Aryl Ketone Synthesis via Pd‐Catalyzed Decarboxylative Coupling of Carboxylate Salts with Aryl Triflates

A bimetallic catalyst system has been developed that for the first time allows the decarboxylative cross‐coupling of aryl and acyl carboxylates with aryl triflates. In contrast to aryl halides, these electrophiles give rise to non‐coordinating anions as byproducts, which do not interfere with the decarboxylation step that leads to the generation of the carbon nucleophilic cross‐coupling partner. As a result, the scope of carboxylate substrates usable in this transformation was extended from ortho‐substituted or otherwise activated derivatives to a broad range of ortho‐, meta‐, and para‐substituted aromatic carboxylates. Two alternative protocols have been optimized, one involving heating the substrates in the presence of Cu^I/1,10‐phenanthroline (10–15 mol %) and PdI₂/phosphine (2–3 mol %) in NMP for 1–24 h, the other involving Cu^I/1,10‐phenanthroline (6–15 mol %) and PdBr₂/Tol‐BINAP (2 mol %) in NMP using microwave heating for 5–10 min. While most products are accessible using standard heating, the use of microwave irradiation was found to be beneficial especially for the conversion of non‐activated carboxylates with functionalized aryl triflates. The synthetic utility of the transformation is demonstrated with 48 examples showing the scope and limitations of both protocols. In mechanistic studies, the special role of microwave irradiation is elucidated, and further perspectives of decarboxylative cross‐couplings are discussed.     

Facile Preparation of Aryl Sulfides Catalyzed by PEG400 and Nickel without Solvent

A variety of aryl sulfides were synthesized by aryl bromides with thiols, with PEG400 and nickel as catalysts under basic conditions in the absence of solvents. This article reported an easy and convenient method for formation of aryl‐sulfur bonds.     

A Facile Route to Aryl Boronates: Room‐Temperature,Copper‐Catalyzed Borylation of Aryl Halides with Alkoxy Diboron Reagents

A simple but effective copper‐catalyzed borylation of aryl halides, including electron‐rich and sterically hindered aryl bromides, with alkoxy diboron reagents occurs under mild conditions (see scheme). Preliminary DFT studies of the mechanism suggest that σ‐bond metathesis between a copper–boryl intermediate and the aryl halide generates the aryl boronate product.

     

Cross‐Coupling of Sodium Sulfinates with Aryl,Heteroaryl, and Vinyl Halides by Nickel/Photoredox Dual Catalysis

An efficient photoredox/nickel catalyzed sulfonylation reaction of aryl, heteroaryl, and vinyl halides has been achieved for the first time. This newly developed sulfonylation protocol provides a versatile method for the synthesis of diverse aromatic sulfones at room temperature and shows excellent functional group tolerance. The electrophilic coupling partners are not limited to aryl, heteroaryl, and vinyl bromides and iodides, but also includes less reactive aryl chlorides as suitable substrates for this transformation.     

Palladium‐Catalyzed Carbonylation Reactions of Aryl Halides and Related Compounds

A CO group richer : (Hetero)arenes are vital intermediates in the manufacture of agrochemicals, dyes, pharmaceuticals, and other industrial products. In the past decades transition‐metal‐catalyzed coupling reactions of aryl halides with all types of nucleophiles have been developed. This Review summarizes recent work in the area of palladium‐catalyzed carbonylation reactions of aryl halides and related compounds (see scheme).

     

Amide Synthesis by Nickel/Photoredox‐Catalyzed Direct Carbamoylation of (Hetero)Aryl Bromides

Herein, we report a one‐electron strategy for catalytic amide synthesis that enables the direct carbamoylation of (hetero)aryl bromides. This radical cross‐coupling approach, which is based on the combination of nickel and photoredox catalysis, proceeds at ambient temperature and uses readily available dihydropyridines as precursors of carbamoyl radicals. The method's mild reaction conditions make it tolerant of sensitive‐functional‐group‐containing substrates and allow the installation of an amide scaffold within biologically relevant heterocycles. In addition, we installed amide functionalities bearing electron‐poor and sterically hindered amine moieties, which would be difficult to prepare with classical dehydrative condensation methods.