Search

A green and efficient strategy for the preparation of trifluoromethylated dihydroisoquinolinones via visible-light-induced radical cyclization of N-allylbenzamides with CF3SO2Na in water at room temperature was developed. This photoinduced reaction generated the desired products in good to excellent yields under simple and mild conditions. [ABSTRACT FROM AUTHOR]

A highly efficient visible light mediated C–C and C–P coupling reactions of sp3 C–H bonds adjacent to the nitrogen atom in tetrahydroisoquinoline derivatives with pronucleophiles such as nitroalkanes, malononitrile, dimethyl malonate and H-phosphonate diesters were achieved by using a magnetic nanoparticle-supported eosin Y bis-benzyltriethylammonium salt (MNPs-Eosin Y) as catalyst and air as the sole oxidant, affording the corresponding products in good to excellent yields under mild reaction conditions. Notably, the supported eosin Y catalyst can easily be separated from the reaction mixture by an external permanent magnet and can be recycled at least eight times without a significant loss of activity. An efficient magnetic nanoparticle-supported eosin Y catalyst was prepared for the visible-light oxidative C–C and C–P bond formation. Image 1 [ABSTRACT FROM AUTHOR]

A visible-light-induced Pd-catalyzed ortho-trifluoromethylation of acetanilides with CF3SO2Na was developed. The reaction proceeded smoothly at room temperature in air without any external photocatalyst or additive, providing the desired products in moderate to good yields with good functional group tolerance and regioselectivity. [ABSTRACT FROM AUTHOR]

An efficient Ag‐promoted reaction of N‐propargyl indoles and arylsulfinic acids to 2‐sulfonated‐9H‐pyrrolo[1,2‐a]indoles was developed. Using arylsulfinic acids as stable and less toxic sulfonylation agent, the reaction proceeded smoothly to give the desired products in good yields and excellent regioselectivity with a broad substrate scope. An efficient Ag‐promoted reaction of N‐propargyl indoles and arylsulfinic acids to 2‐sulfonated‐9H‐pyrrolo[1,2‐a]indoles was developed. The reaction underwent smoothly to give the desired products in good yields and excellent regioselectivity with broad substrate scope using arylsulfinic acids as stable and less toxicity sulfonylating agent. [ABSTRACT FROM AUTHOR]

A simple and efficient transition‐metal‐free protocol for the regioselective C–H bond fluorination of 8‐aminoquinoline scaffolds with Selectfluor was developed. The reaction has a broad substrate scope and provides facile access to the corresponding C‐5 fluorinated quinolines in good yields. [ABSTRACT FROM AUTHOR]

Visible-light-induced oxidative formylation of N-alkyl-N-(prop-2-yn-1-yl)anilines with molecular oxygen in the absence of an external photosensitizer was developed and afforded the corresponding formamides in good yields under mild conditions. The investigation of the mechanism disclosed that both the starting material and the product act as photosensitizers, and 1O2 and O2Ṗ− are generated through energy transfer and a single electron transfer pathway and play an important role in the reaction. [ABSTRACT FROM AUTHOR]

A facile synthesis of diaryl 1,2-diketones from diarylalkynes under visible-light irradiation was developed. The reaction proceeded smoothly through a thiyl radical catalyzed oxidation by molecular oxygen under mild conditions and generated the desired products in excellent yields with good tolerance of functional groups. [ABSTRACT FROM AUTHOR]

A simple and efficient strategy for the preparation of 3-acylindoles via visible-light promoted C3-acylation of free (NH)- and N-substituted indoles with α-oxocarboxylic acids was developed. The reaction tolerates a wide range of functional groups, and the corresponding 3-acylindoles were obtained in high yields under mild conditions. [ABSTRACT FROM AUTHOR]

An efficient C−H acylation of azo- and azoxybenzenes with α-keto acids has been developed by a combination of palladium catalysis and visible-light photoredox catalysis at room temperature under 1.5 W blue LED irradiation. This method tolerates a variety of disubstituted azo- and azoxybenzenes, as well as α-keto acids regardless of the nature of the substituents. A number of aryl ketones were obtained in good yields under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Abstract: A series of dinuclear N-heterocyclic carbene (NHC) palladium complexes [PdCl2(NHC)]2(μ-L) (1–6, L = diphosphine ligands) has been synthesized and fully characterized by 1H NMR, 13C NMR and 31P NMR spectroscopies, elemental analysis, IR spectroscopy, and X-ray crystal structural study. The solid-state structures of 1–6 show dinuclear frameworks with two palladium(II) centres were held together by bridging diphosphine ligands. Each palladium centre was coordinated by an N-heterocyclic carbene ligand, a phosphorus atom and two chloro ions in a trans-arrangement. Further explorations of the catalytic potential of the dinuclear carbene palladium complexes as catalysts for Pd-mediated transformations have been examined under microwave irradiation conditions and the title complexes (1–6) displayed good catalytic activities in Buchwald–Hartwig aminations of aryl chlorides. [Copyright &y& Elsevier]

A green organic reaction of aliphaticprimary amines with 1,3-diketonespromoted by 30% aqueous H2O2has been developed.It provides an inexpensive, regioselective, and efficient approachto 1H-pyrrol-3(2H)-ones with highyields from the simple and readily available starting materials inone pot via multicomponent tandem cyclization reactions and C–Ccleavage under very mild and environmentally friendly reaction conditions. [ABSTRACT FROM AUTHOR]

In continuing our efforts to develop economical and ecofriendly synthetic protocols, we present a proline-palladium catalyst supported on magnetic nanoparticles (0.5 mol %) for oxidation by molecular oxygen. The supported Pd catalyst shows high activity in the oxidation of alcohols into the corresponding carbonyl compounds where easy catalyst recovery and excellent recycling efficiency are observed. It is possible to recover and reuse the grafted palladium catalysts at least eight times without significant loss of its catalytic activity. [ABSTRACT FROM AUTHOR]

The rapid and efficient direct C2-arylation of free (NH)-indoles with arylsulfinic acids proceeded through a microwave-accelerated palladium-catalyzed desulfitation reaction. By using PdCl2 as a catalyst, silver acetate as an oxidant, and H2SO4 as an additive, arylsulfinic acids with both electron-donating and electron-withdrawing groups underwent desulfitative coupling with an array of free (NH)-indoles, thereby selectively providing C2-arylindoles in good yields. [ABSTRACT FROM AUTHOR]

Avoiding additives: A highly efficient and mild Pd‐catalyzed decarboxylative ortho‐acylation of azobenzenes with α‐oxocarboxylic acids was developed that provides an alternative route to acylated azo compounds. This decarboxylative acylation process was completed in the absence of any additives at ambient temperature, to afford the acylated azobenzenes in moderate to good yields (see scheme). [ABSTRACT FROM AUTHOR]

A novel palladium-catalyzed direct alkoxycarbonylation of 2-arylpyridines, 2-arylquinolines, benzo[ h]quinolines, 2-phenylpyrimidines, N-pyrimidine pyrroles and N-pyrimidine indoles via aromatic CH bond activation and selective CC cleavage of α-keto esters has been developed. The method has the advantages of wide functional group tolerance, high selectivity, broad range of substrates and good yields. [ABSTRACT FROM AUTHOR]

Abstract: A MOF-supported Cu(I) catalyst bearing N,O-chelating ligand was prepared through postsynthetic modification of IRMOF-3 and used as an efficient heterogeneous catalyst for three-component coupling reaction of aldehyde, alkyne, and amine. The catalyst exhibited both high catalytic activity and stability for the reaction and the framework of Cu(I) catalyst was mainly maintained after the catalyst was reused for four times. [Copyright &y& Elsevier]

N-Arylation of imidazoles with arylboronic acids was efficiently carried out in the presence of a catalytic amount of SiO2-NHC-CuI in methanol at room temperature under base-free reaction conditions. The reactions of a variety of arylboronic acids with imidazoles generated the corresponding products N-arylimidazoles in good to excellent yields. In addition, SiO2-NHC-CuI could be recovered and recycled for six consecutive trials without significant loss of its reactivity. [ABSTRACT FROM AUTHOR]

Abstract: A novel Merrifield resin supported phenanthroline–Cu(I) complex has been developed and used as a highly efficient and recyclable catalyst in the reaction of 2-halobenzenamines with isothiocyanates for the synthesis of 2-aminobenzothiazoles. The reactions were applicable to a variety of 2-halobenzenamines and isothiocyanates, and generated the corresponding 2-aminobenzothiazoles in good yields under mild reaction conditions. Moreover, the catalyst was quantitatively recovered from the reaction mixture by a simple filtration and reused for ten cycles with almost consistent activity. [Copyright &y& Elsevier]

Abstract: An effective, convenient, and mild coupling reaction of benzylic alcohols with terminal alkynes has been developed. As an effective Lewis acid, Cu(OTf)2-catalyzed arylmethylation of terminal alkynes with benzylic alcohols generated the corresponding products in BrCH2CH2Br with good yields in the absence of ligand, base, and additive. [Copyright &y& Elsevier]

Abstract: A new silica immobilized palladium-phosphine complex has been developed. It was found to be an efficient catalyst for Suzuki–Miyaura cross-coupling reactions under mild conditions. It is important to note that the supported catalyst could be reused at least 10 times without a significant loss of catalytic activity. [Copyright &y& Elsevier]

Abstract: A novel SiO2–NHC–Cu(I) 3b was developed and used as a highly efficient catalyst for [3+2] cycloaddition of organic azides and terminal alkynes. In the presence of SiO2–NHC–Cu(I) 3b (1mol %), the reactions of terminal alkynes with organic azides underwent smoothly to generate the corresponding regiospecific 1,4-disubstituted 1,2,3-triazoles in excellent yields under solvent-free reaction conditions at room temperature. Furthermore, catalyst 3b was quantitatively recovered from the reaction mixture by a simple filtration and reused for 10 cycles without loss of its activity. [Copyright &y& Elsevier]

Abstract: The development of a highly efficient, polystyrene-supported NHC–Ag(I) catalyst for the three-component coupling reactions of aldehydes, alkynes, and amines (A3-coupling) was described. In the presence of PS–NHC–Ag(I) (2mol%), the A3-reactions were carried out at room temperature under solvent-free reaction conditions and the corresponding propargylamines were generated in good to excellent yields. Furthermore, the catalyst could be reused at least 12 times without a significant loss of its catalytic activity. [Copyright &y& Elsevier]

Abstract: A novel silica gel supported pyrrolidine-based chiral ionic liquid 6a has been developed and found to be a highly effective catalyst for the Michael addition reaction of ketones with nitrostyrenes. The reactions generated the corresponding products in good yields (up to 94%), excellent enantioselectivities (up to >99% ee), and high diastereoselectivities (up to >99:1 dr). In addition, the catalyst 6a can be reused at least five times without a significant loss of catalytic activity and stereoselectivity. [Copyright &y& Elsevier]

Abstract: Recycling copper(I) immobilized on organic–inorganic hybrid material behaves as a very efficient heterogeneous catalyst in the three-component Mannich coupling reaction of aldehydes, terminal alkynes, and amines via C–H activation to afford the corresponding products in good to excellent yields under solvent-free reaction conditions. [Copyright &y& Elsevier]

Abstract: In the absence of ligand, copper and amine, a recoverable nanoparticle palladium(0) catalyzed Sonogashira reaction of aryl iodides and bromides with terminal alkynes was developed. The protocol involved the use of an environmental-friendly reaction system with ethanol as the solvent, potassium carbonate as a base, and poly(vinylpyrrolidone) (PVP) supported nanosized palladium metal colloids as the catalyst. The palladium metal was recovered and recycled by a simple decantation of the reaction solution and used for eight consecutive trials without significant loss of its reactivity. [Copyright &y& Elsevier]

A microwave irradiated solventless Sonogashira coupling reaction catalyzed by nanosize nickel(0) powder on potassium fluoride–alumina mixture has been developed. Terminal alkynes couple with aryl, alkenyl iodide, and aryl bromide in the presence of cuprous iodide, triphenylphosphine, and ultrafine particle nickel(0) on potassium fluoride–alumina to generate the corresponding cross-coupling products. [ABSTRACT FROM AUTHOR]

A Sonogashira coupling reaction of aromatic iodides and bromides with terminal alkynes in the presence of palladium powder, potassium fluoride, cuprous iodide, and triphenylphosphine in aqueous media was developed. The reaction generates the corresponding coupling products aryl alkynes in good to excellent yields. [ABSTRACT FROM AUTHOR]

Tellurium metal in near-critical water (275°C) provides a novel and efficient method for the reduction of azides, producing amines in good yields. [ABSTRACT FROM AUTHOR]

A novel two-step aldehyde homologation procedure for the preparation of methyl ketones has been developed, which involves the use of 1,1-dibromo-1-alkenes as precursors and zinc metal as mediator in near-critical water. [Copyright &y& Elsevier]

A simple strategy to 3‐acylated quinoxalin‐2(1H)‐ones via a photo‐induced cross‐dehydrogenative coupling of quinoxalin‐2(1H)‐ones with commercially available aldehyde under metal free conditions without an external photocatalyst was developed. In this transformation, various 3‐acylated quinoxalin‐2(1H)‐ones were generated in high yields with good functional‐group tolerance. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed ortho-acylation reaction of azoxybenzenes with α-oxocarboxylic acids was developed in the presence of K2S2O8. The established methodology provides a direct approach to obtain acylated azoxybenzenes in good yields. [ABSTRACT FROM AUTHOR]

A novel and efficient Cu-promoted decarboxylative direct C3-acylation of N-substituted indoles with α-oxocarboxylic acids for the synthesis of 3-acylindoles was developed. [ABSTRACT FROM AUTHOR]

A novel metallic samarium promoted reduction of sodium alkyl thiosulfates in the absence of an activating agent occurs to afford the corresponding disulfides with good yields in water at 90°C. [Copyright &y& Elsevier]

A simple and effective method for the synthesis of 9‐sulfenylphenanthrenes was developed via BF3 ⋅ OEt2‐mediated annulation of 2‐alkynyl biaryls with N‐arylthio succinimides at room temperature. Through this methodology, a series of 9‐sulfenylphenanthrenes could be efficiently and conveniently obtained in good to excellent yields under mild and metal‐free conditions. [ABSTRACT FROM AUTHOR]

An efficient photoinduced strategy for the hydrogenation and arylsulfonylation of alkenes has been developed. The reaction afforded a range of hydrogenated products and sulfonated oxindoles in high yields under external photocatalyst‐free, oxidant‐ and reductant‐free conditions. Mechanistic investigations suggested this transformation is driven by the photochemical activity of hydrogen bond donor‐acceptor complex, generated from the substrates of arylsulfinic acids and C6‐(vinyl sulfone)phenanthridines or N‐arylacrylamides via hydrogen bond interaction. [ABSTRACT FROM AUTHOR]

An unprecedented reaction between quinoline N‐oxides with O‐benzoylhydroxylamines was developed by using CuCl as catalyst, generating deoxygenative products of 2‐aminoquinolines in good yields. 1,2‐Dichloroethane (DCE) as solvent was also served as reducing agent to cleave the N–O bond with no additional reductant needed in the reaction. An unprecedented reaction between quinoline N‐oxides with O‐benzoylhydroxylamines was developed by using CuCl as catalyst, generating deoxygenative products of 2‐aminoquinolines in good yields. 1,2‐Dichloroethane (DCE) as solvent also served as reducing agent to cleave the N–O bond with no additional reductant needed in the reaction. [ABSTRACT FROM AUTHOR]

An efficient C-H acylation of azo- and azoxybenzenes with aromatic α-keto acids is developed combining palladium and visible-light photoredox catalysis under blue LED irradiation. [ABSTRACT FROM AUTHOR]

32 examples [ABSTRACT FROM AUTHOR]

Photocatalysis Visible ‐ light ‐ induced photoredox catalysis has emerged as a powerful tool by unique single ‐ electron ‐ transfer process in organic synthesis, and transition ‐ metal ‐ catalyzed C−H activation dramatically shortened the route to the target molecules. Especially, dual catalysis realized by merging visible ‐ light photoredox and transition ‐ metal catalysis has recently attracted much more attention. In their Communication on page 2236 ff., L. Wang et al. developed a combination catalysis of Pd and acridinium salt (a photoredox catalyst) for the ortho ‐ C−H acylation of azobenzenes and azoxybenzenes with α ‐ keto acids at room temperature under visible ‐ light irradiation. [ABSTRACT FROM AUTHOR]

An electrochemical electrophilic bromination/spirocyclization of N-benzyl-acrylamides with 2-bromoethan-1-ol as the brominating reagent has been developed. The paired electrolysis employs low concentrations of bromine produced from both cathodic reduction and anodic oxidation as an electrophile, and realizes an H2O-involved electrophilic spirocyclization. A number of unexplored brominated 2-azaspiro[4.5]decanes are obtained with satisfactory yields under mild conditions, and the reaction exhibits good efficiency at the gram-scale synthesis. In addition, this approach is further highlighted by late-stage transformations and synthetic applications in constructing cyclohepta[c]pyrrole-1,6-diones via debromination tandem cyclization of brominated 2-azaspiro[4.5]decanes. [ABSTRACT FROM AUTHOR]

An abstract of the article "A Sulfenylation Reaction: Direct Synthesis of 3-Arylsulfinylindoles From Arylsulfinic Acids and Indoles in Water" is presented.

The reaction can be scaled up. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Dinuclear N-Heterocyclic Carbene Palladium(II) Complexes as Efficient Catalysts for the Buchwald?Hartwig Amination" by J. Yang and others, published in the "Journal of Organometallic Chemistry" in 2014.

An abstract of the article "KOAc-Promoted Alkynylation of a-CH―Bonds of Ethers with Alkynyl Bromides under Transition-Metal-Free Conditions" by J. Zhang, P. Li, and L. Wang is presented.

The article presents Chemical equations for the article "H2O2-Promoted Reactions of Aliphatic Primary Amines with 1,3-Diketones for the Synthesis of 1H-Pyrrol-3(2H)-ones at Ambient Temperature in Water" by X. Sun and others in the periodical "Organic Letters" in 2014.

An abstract of the article "Palladium Supported on Magnetic Core-Shell Nanoparticles: An Efficient and Reusable Catalyst for the Oxidation of Alcohols into Aldehydes and Ketones by Molecular Oxygen," by L. Zhang, P. Li, J. Yang, M. Wang, and L. Wang is presented.

The selective direct C2-arylation of indoles with arylsulfinic acids proceeds through a microwave-accelerated palladium-catalyzed desulfitation reaction. [ABSTRACT FROM AUTHOR]

The article presents chemical equations for the article "A Highly Efficient Palladium-Catalyzed Decarboxylative ortho-Acylation of Azobenzenes with α-Oxocarboxylic Acids: Direct Access to Acylated Azo Compounds" by H. Li and colleagues, published in "Chemistry: A European Journal" in 2013 issue.

A diagram is presented which explains the unprecedented ortho-acylation of azoxybenzenes with α- oxocarboxylic acids by C—H activation and decarboxylation using palladium (Pd) catalysts.

A diagram is presented which shows the direct alkoxycarbonylation of aromatic carbon-hydrogen (C-H) bonds with palladium as catalyst.