Iron‐Catalyzed C?N Cross‐Coupling of Sulfoximines with Aryl Iodides

An inexpensive and experimentally simple, iron‐catalyzed N‐arylation reaction of NH‐sulfoximines with aryl iodides is reported. This complementary method to the known palladium‐ and copper‐catalyzed ones features the use of a combination of environmentally friendly FeCl₃ and N,N′‐dimethylethylenediamine (DMEDA) as catalytic system and allows the efficient preparation of various N‐arylsulfoximines in high yields.     

Iron‐Catalyzed C?C Bond Cleavage and C?N Bond Formation

A novel approach for C N bond formation was developed by iron‐catalyzed C C bond cleavage. Anilines and sulfonamides reacted smoothly with 2‐substituted 1,3‐diphenylpropane‐1,3‐diones to afford N‐alkylation products, in which the 1,3‐dicarbonyl group acts as a leaving group in the presence of an iron catalyst. The reversible C C bond cleavage plays a driving force to give the thermodynamically stable products. The method is complementary to the previous methods for C N bond formation.     

Zinc‐Catalyzed Organic Synthesis: C?C,C?N,C?O Bond Formation Reactions

Zinc is the 24^th most abundant element in the Earth’s crust. Since the discovery of pure zinc metal in the 18^th century, the main application of zinc metal is as materials. Because zinc salts are abundant, cheap, non‐toxic, and exhibit environmentally benign properties, organic chemists have been interested in using zinc salts as catalysts in organic synthesis during the last three decades. Within this review, we have summarized the progress on applications of zinc salts in organic reactions. Our the target is to emphasize the special properties of zinc catalysts, and further promote the interest of organic chemists.     

Auto‐Tandem Catalysis: Synthesis of Substituted 11H‐Indolo[3,2‐c]quinolines via Palladium‐Catalyzed Intermolecular C?N and Intramolecular C?C Bond Formation

D ‐Ring substituted 11H‐indolo[3,2‐c]quinolines ( 4 ) have been prepared via auto‐tandem consecutive intermolecular Buchwald‐Hartwig reaction and intramolecular palladium‐catalyzed arylation on 4‐chloroquinoline ( 1 ) with N‐unsubstituted 2‐chloroanilines ( 2 ). The reported 11H‐indolo[3,2‐c]quinolines ( 4 ) represent the first examples in which tandem catalysis has been used to construct N‐unsubstituted carbolines.     

Palladium‐Catalyzed C?N Cross‐Coupling of N′‐Monosubstituted Sulfondiimines with Aryl Bromides

A general method for the N‐arylation of sulfondiimines with aryl bromides using tris(dibenzylideneacetone)dipalladium(0) [Pd₂(dba)₃] and 2‐dicyclohexylphosphino‐2′,6′‐diisopropoxybiphenyl (RuPhos) as catalyst system was developed. A new benzothiazine was obtained, and a protocol for the cleavage of para‐methoxyphenyl (PMP) groups in PMP‐protected sulfondiimines has been found, which provides access to synthetically useful NH‐derivatives, that are difficult to prepare by other means.     

Palladium‐Catalyzed Oxidative sp2 C?H Bond Acylation with Aldehydes

An efficient method was developed for the direct acylation of arene sp² C H bonds with aldehydes using palladium acetate as catalyst and peroxide as oxidant. The solvent‐free oxidative acylation reaction assisted by a pyridine directing group provides an easy access to aromatic, aliphatic, and optical active ketones.     

Cadmium(II)‐Catalyzed C?N Cross‐Coupling of Amines with Aryl Iodides

Cadmium diacetate dihydrate [Cd(OAc)₂⋅2 H₂O] in combination with ethylene glycol catalyzes efficiently the C N cross‐coupling of amines with aryl iodides by a benzyne mechanism. Alkyl, aryl and heterocyclic amines are compatible with this system affording the aminated products in high to excellent yield.     

Synthesis of N,N′-bis(P,P-dialkylthiophosphinyl)diamines R2P(S)-NH?R′?NH?P(S)R2

N,N′-Bis(P,P-dialkylthiophosphinyl)diamines 1a-e were obtained from Et2P(S)Br and H2N R′ NH2 with elimination of HBr. Compounds 2a-e were prepared by sulfuration of R2P NH R′ NH PR2 that were generated without isolation from NH2-R′-NH2 and t-Bu2PCl.     

Carbon Nitride‐Catalyzed Photoredox C?C Bond Formation with N‐Aryltetrahydroisoquinolines

In this communication we describe the oxidative C C bond formation of tertiary amines with various nucleophiles under very mild and environmental friendly conditions by using mesoporous graphitic carbon nitride (mpg‐C₃N₄) semiconductor as a heterogeneous, metal‐free photosensitizer in combination with visible light and oxygen as the terminal oxidation agent. This system can be further combined with proline‐organocatalysis to achieve oxidative tandem photocatalysis, demonstrating a rich cascade of chemical possibilities of the current photosynthesis system.     

Lewis Acid‐Catalyzed Generation of C?C and C?N Bonds on π‐Deficient Heterocyclic Substrates

Focused microwave irradiation of a series of halogenated nitrogen heterocycles and different kinds of nucleophiles in the presence of a catalytic amount of indium trichloride leads to the efficient and completely regioselective generation of aromatic C C and C N bonds. The method is simple, rapid, general and inexpensive, and can be performed without the use of dried solvents. Most of the synthetized compounds are new and in many cases the work‐up required only filtration. Furthermore, this is the first example of the use of a Lewis acid as a catalyst for heteroarylation, vinylation and amination reactions on π‐deficient heterocyclic substrates.

     

Rhodium(III)‐Catalyzed C(sp2)?H Activation and Electrophilic Amidation with N‐Fluorobenzenesulfonimide

An electrophilic amidation via a cationic rhodium(III)‐catalyzed C(sp²) H activation has been developed with the commercially available N‐fluorobenzenesulfonimide as the amino source under external oxidant‐free conditions. This amidation requires only a catalytic amount of base and exhibits excellent functional group tolerance and regioselectivity, providing a new avenue in direct C(sp²) H amidation.     

Palladium‐Catalyzed Decarboxylative Coupling of α‐ Oxocarboxylic Acids with C(sp2)?H of 2‐Aryloxypyridines

An efficient palladium‐catalyzed decarboxylative ortho‐acylation of 2‐aryloxypyridines with α‐oxocarboxylic acids is described. In this new transformation, the aromatic C(sp²) H bond was successfully acylated to give diverse aromatic ketones regioselectively in moderate to good yields. The pyridine group can be removed easily after the acylation to give the corresponding 2‐hydroxy aromatic ketones.     

Surface characterization of hydrophilic coating obtained by low‐pressure CH4?O2 plasma treatment on a polypropylene film

The use of surface treatments at industrial level is generalized as they allow obtaining a wide variety of properties such as soft in the touch, hydrophilic behavior, and biocompatibility. The use of low‐pressure plasma techniques with organic gases or organic mixtures is an easy way to obtain surface coatings very small in depth through plasma‐polymerization processes that can be assimilated to a plasma‐enhanced chemical vapor deposition (PECVD) process. In this work, we have carried out a plasma‐polymerization process on a polypropylene (PP) film to obtain a hydrophilic coating. To obtain this, the film surface has been treated on a low‐pressure plasma reactor with a methane–oxygen mixture gas with a volume ratio of 80 : 20, respectively. The chemistry changes in the outermost layers of the deposited coating have been investigated with X‐ray photoelectron spectroscopy (XPS). The different processes that take part as a consequence of the interaction between the plasma gas species and the PP film surface mainly drive to the deposition of an organic layer, which is functionalized with oxygen‐based species as XPS study reveals. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Asymmetric meso‐Epoxide Ring‐Opening with Trimethylsilyl Cyanide Promoted by Chiral Binuclear Complexes of Titanium. Dichotomy of C?C versus C?N Bond Formation

In the presence of chiral catalysts derived from the same chiral hexadentate ligand and aluminium, zinc or titanium ions, the reaction between cyclohexene oxide and trimethylsilyl cyanide can be controlled to give predominantly either the nitrile (up to 99% ee) or the isonitrile product (up to 94% ee). The metal ion, ligand stereochemistry and base concentration all play a role in determining the product ratio.     

Copper‐Mediated Sulfonylation of Aryl C(sp2)?H Bonds with Sodium and Lithium Sulfinates

A copper‐mediated direct sulfonylation of aryl C(sp²) H bonds with sodium and lithium sulfinates is reported. Various aryl sulfones were synthesized in moderate to excellent yields with good functional group tolerance.

     

Stoichiometric Reductive C?N Bond Formation of Arylgold(III) Complexes with N‐Nucleophiles

The reductive formation of substituted anilines from amines and three well‐defined aryl‐ gold(III) complexes, i.e., dichloro(2,6‐lutidine)phen‐ ylgold(III) ( 2 ), dichloro(2,6‐lutidine)‐p‐tolylgold(III) ( 3 ), and chlorobis(triphenylphosphine)phenylgold(III) chloride ( 4 ) was studied. The reaction is stoichiometric in gold and represents a key step of a potential gold‐catalyzed intermolecular amination reaction of arenes. It proceeds smoothly with a broad range of N‐nucleophiles in the presence of sodium acetate (NaOAc) and enables the selective formation of N‐substituted anilines in good yields. A mechanistic pathway is proposed and discussed as well.     

Magnetically Retrievable Nano Crystalline Nickel Ferrite‐ Catalyzed Aerobic,Ligand‐Free C?N,C?O and C?C Cross‐ Coupling Reactions for the Synthesis of a Diversified Library of Heterocyclic Molecules

A new nickel ferrite nano‐crystal‐catalyzed, ligand‐free strategy for the construction of C N, C O, and C C bonds is presented, in which easily available nitrogen and oxygen nucleophiles, aryl/heteroaryl halides and arylboronic acids are used for the cross‐coupling reactions. The reactions can be performed at low catalyst loadings with excellent functional group tolerance and chemoselectivity. A variety of functional groups are compatible with the reaction conditions, including nitro, methoxy, as well as acid‐ and base‐sensitive heteroaromatic groups. This unprecedented chemistry nicely complements classical methods for the N‐arylation of amines/heteroamines, the O‐arylation of phenols/hydroxycoumarins and biaryl/heteroaryl synthesis. The low cost, easy to handle nature and the simplicity of this catalytic system render the method competitive with comparable copper‐ and palladium‐based protocols which require the presence of sophisticated ligands. Nickel ferrite magnetic nanoparticles were prepared by a simple hydrothermal method and characterized by using XRD, TEM image, energy dispersive X‐ray analysis, XPS and FT‐IR. The easy recovery of the catalyst and high yield of the products make the protocol attractive, sustainable and economic. The catalyst was reused for five cycles with almost unaltered catalytic activity.

     

Copper‐Catalyzed C?NH2 Arylation of 2‐Aminobenzimidazoles and Related C‐Amino‐NH‐azoles

A copper(II)‐catalyzed selective C NH₂ arylation of 2‐aminobenzimidazoles and related C‐amino‐NH‐azoles was achieved in presence of 2,2′‐bipyridine and cesium carbonate at 60 °C under open air conditions and this is first method for the copper‐catalyzed selective C NH₂ arylation in the presence of other reactive nucleophilic sites. Previously unexplored heteroaromatics possessing multiple nucleophilic sites that are selectively arylated at the C NH₂ position are obtained, providing an exceptional tool for rapid delivery of a diverse array of medicinally important C NH(aryl) derivatives of aminoazoles without any protection/deprotection of ring N H bonds. It is first example for the selective C NH₂ arylation of 5‐aminoindazole, 4‐aminopyrazole, 5‐aminopyrazole, 9H‐purine‐6‐amine, and 1H‐pyrazolo[3,4‐d]pyrimidin‐4‐amine derivatives.