Cu(II)-Mediated Sulfonylation of (Hetero)arenes with TosMIC Using Monodentate Directing Groups.

Monodentate chelation-assisted direct -C-H sulfonylation of (hetero)arenes using TosMIC as the novel sulfonylating reagent has been developed. A broad range of substrates, including indolines, indoles, 2-phenylpyridines, and others were well tolerated to afford the corresponding products in moderate to good yields. Mechanistic studies revealed that the sulfonyl radical might be involved.

Water-Soluble Metallo-Supramolecular Nanoreactors for Mediating Visible-Light-Promoted Cross-Dehydrogenative Coupling Reactions.

Water-soluble metallo-supramolecular cages with well-defined nanosized cavities have a wide range of functions and applications. Herein, we design and synthesize two series of metallo-supramolecular octahedral cages based on the self-assembly of two congeneric truxene-derived tripyridyl ligands modified with two polyethylene glycol (PEG) chains, i.e.

Synthesis of a Tetrahedral Metal-Organic Supramolecular Cage with Dendritic Carbazole Arms.

In recent years, incredible endeavors have been devoted to the design and self-assembly of discrete metal-organic cages (MOCs) with expanding intricacy and functionality. The controlled synthesis of metal-organic supramolecular cages with large branched chains remains an interesting and challenging work in supramolecular chemistry. Herein, a tetrahedral metal-organic supramolecular cage (ZnL) containing 12 dendritic carbazole arms is unprecedentedly constructed through coordination-driven subcomponent self-assembly and characterized in different ways.

New NNN pincer copper complexes as potential anti-prostate cancer agents.

Eleven novel NNN Cu(II) complexes supported by a tridentate bis(imidazo[1,2-α]pyridin-2-yl)pyridine ligand were synthesized and characterized by elemental analysis, HRMS, and X-ray determination. Target prediction and docking studies indicated that these pincer complexes formed hydrogen bonds with Asp33 and Gly35 of Cathepsin D protein, which is highly associated with prognosis of advanced prostate cancer. Furthermore, they exhibited anti-proliferation activity in both androgen-sensitive and androgen-insensitive prostate cancer cells according to WST-1 assay results.

Cu(II)-Catalyzed N-Directed Distal C(sp)-H Heteroarylation of Aliphatic -Fluorosulfonamides.

A copper-catalyzed δ-regioselective C(sp)-H heteroarylation of -fluorosulfonamides has been developed. A broad range of heteroarenes were well tolerated and reacted with various -fluorosulfonamides to give the corresponding heteroarylated amides in good yields. Notably, all types (1°, 2°, and 3°) of δ-C(sp)-H bonds in the -fluorosulfonamides could be regioselectively activated through the 1,5-HAT process.

Fe(III)-Catalyzed -Amidomethylation of Secondary and Primary Anilines with TosMIC.

A Fe(III)-catalyzed -amidomethylation of secondary and primary anilines with -toluenesulfonylmethyl isocyanide (TosMIC) in water is described. TosMIC plays dual roles as the source of methylene as well as an amidating reagent to form α-amino amides in this multicomponent reaction. The combination of TosMIC and other isocyanides was also investigated to give the desired products in acceptable yields.

Regioselective N-F and α C(sp)-H Arylation of Aliphatic -Fluorosulfonamides with Imidazopyridines.

A regioselective arylation of aliphatic -fluorosulfonamides with imidazopyridines enabled by breaking of N-F and α C(sp)-H bond to form C-N and C-C bonds was described. With CuCl as the catalyst, a radical mechanism was proposed to produce N-arylated aliphatic sulfonamides via a N radical intermediate. Importantly, under acidic conditions, an in situ generated imine was the possible intermediate, which was trapped by imidazopyridines to form α C(sp)-H arylated aliphatic sulfonamides.

Iron-Mediated Selective Sulfonylmethylation of Aniline Derivatives with -Toluenesulfonylmethyl Isocyanide (TosMIC).

An iron-mediated highly selective C-H sulfonylmethylation of aniline derivatives with -toluenesulfonylmethyl isocyanide in a mixture solvent of HO and PEG under an Ar atmosphere has been realized. This transformation proceeds with operational convenience, use of earth-abundant metal catalyst and nontoxic media, broad substrate scope, and good functional group tolerance. The current methodology could be applied to the regioselective C-H sulfonylmethylation of indolines, tetrahydroquinolines, and tertiary anilines.

NaOH-Mediated Direct Synthesis of Quinoxalines from -Nitroanilines and Alcohols via a Hydrogen-Transfer Strategy.

A NaOH-mediated sustainable synthesis of functionalized quinoxalines is disclosed via redox condensation of -nitroamines with diols and α-hydroxy ketones. Under optimized conditions, various -nitroamines and alcohols are well tolerated to generate the desired products in 44-99% yields without transition metals and external redox additives.

Ruthenium-Catalyzed C(sp)-H Bond Bisallylation with Imidazopyridines as Directing Groups.

A Ru(II)-catalyzed bisallylation of imidazopyridines with vinylcyclopropanes or vinyl cyclic carbonate has been successfully realized. Notably, pharmacophore imidazopyridine was utilized as an intrinsic directing group, which gave access to value-added bisallylated products in high yields via double tandem C-H and C-C/C-O activation. The current methodology was featured with broad substrate scope, good functional group compatibility, and operational simplicity.

Rh(III)-Catalyzed C-H Cyanation of 2-Indazole with -Cyano--phenyl--toluenesulfonamide.

A Rh(III)-catalyzed direct cyanation of 2-indazoles with -cyano--phenyl--toluenesulfonamide has been realized via a chelation-assisted strategy. The methodology enables regioselective access to various ortho-cyanated phenylindazoles in good yields with a broad substrate scope and good functional group compatibility. The obtained cyanated indazoles could further be converted into other value-added chemicals.

Temperature-Controlled Chalcogenation and Chalcogenocyanation of Imidazopyridines in Water under Transition Metal-Free Conditions.

A sustainable and transition metal-free approach for C3 chalcogenation and chalcogenocyanation of imidazopyridines with KXCN (X = S or Se) has been developed under mild conditions. Importantly, this reaction was performed in the presence of catalytic iodine in aqueous medium, which afforded either chalcogenated or chalcogenocyanated imidazopyridines under temperature control. The current protocol featured a broad substrate scope, transition metal-free and organic solvent-free conditions, operational convenience, and gram-scale production.

Solvent-free and room temperature microwave-assisted direct C7 allylation of indolines sequential C-H and C-C activation.

A Ru or Rh-catalyzed efficient and atom-economic C7 allylation of indolines with vinylcyclopropanes was developed sequential C-H and C-C activation. A wide range of substrates were well tolerated to afford the corresponding allylated indolines in high yields and / selectivities under microwave irradiation. The obtained allylated indolines could further undergo transformations to afford various value-added chemicals.

Cu-Catalyzed Direct C7 Sulfonylation of Indolines with Arylsulfonyl Chlorides.

An efficient Cu-catalyzed direct sulfonylation of indolines with easily accessible sulfonyl chlorides has been realized under an air atmosphere via a chelation-assisted strategy. This protocol exhibits several unique characteristics, including broad substrate scope, good functional group tolerance, and operational convenience, which enable a regioselective access to a variety of C-7 functionalized indoline scaffolds in moderate to good yields. The mechanistic study reveals that the sulfonyl radical might be involved in this transformation.

Ditopic Chiral Pineno-Fused 2,2':6',2″-Terpyridine: Synthesis, Self-Assembly, and Optical Properties.

The syntheses of 4'-substituted chiral 2,2':6',2″-terpyridine (tpy) ligands with predetermined configurations and directionalities are rather limited in the supramolecular chemistry field. In this study, a carbazole-linked ditopic chiral ligand was synthesized using 4'-bromo-substituted pineno-fused tpy as the precursor. Upon complexation with Cd(NO)·4HO and Zn(NO)·6HO, two enantiomerically pure metallosupramolecules, [CdL] and [ZnL], have been self-assembled and characterized by NMR, electrospray ionization-mass spectrometry, traveling wave ion mobility-mass spectrometry, and DOSY analysis.

Oxidative sulfonamidomethylation of imidazopyridines utilizing methanol as the main C1 source.

An efficient one pot, three component synthesis of C3 sulfonamidomethylated imidazopyridines has been disclosed under metal-free conditions, which utilized the commercially available and renewable reagent methanol as the main methylene source. A wide range of substituted imidazopyridines and sulfamides/amines were well tolerated to afford the corresponding products in up to 92% yield. In the isotopic labelling experiment, it was found that a minor part of the methylene also originated from DTBP.

Copper-Catalyzed Double Thiolation To Access Sulfur-Bridged Imidazopyridines with Isothiocyanate.

A copper(I)-catalyzed sulfur-bridged dimerization of imidazopyridines has been developed using isothiocyanate as the sulfur source. This method enables a switchable synthesis of bis(imidazo[1,2- a]pyridin-3-yl)sulfanes or bis(2-(imidazo[1,2- a]pyridin-2-yl)phenyl)sulfanes in the presence of 4-dimethylaminopyridine (DMAP) or KCO when different imidazopyridines were employed. Under optimized conditions, a variety of sulfur-bridged imidazopyridines were obtained in good yields.

Copper-Mediated C-H Amination of Imidazopyridines with N-Fluorobenzenesulfonimide.

A copper-mediated direct C3 amination of imidazopyridines has been disclosed under additive-free conditions in short reaction times. This methodology utilizes commercially available N-fluorobenzenesulfonimide (NFSI) as the amino source, which exhibits broad substrate scope and good functional group tolerance. The obtained C3-aminated imidazopyridines can undergo further desulfonylation transformations.

Cobalt-catalyzed -selective alkoxylation of 1-naphthylamine derivatives.

A cobalt-catalyzed C(sp)-H alkoxylation of 1-naphthylamine derivatives has been disclosed, which represents an efficient approach to synthesize aryl ethers with broad functional group tolerance. It is noteworthy that secondary alcohols, such as hexafluoroisopropanol, isopropanol, isobutanol, and isopentanol, were well tolerated under the current catalytic system. Moreover, a series of biologically relevant fluorine-aryl ethers were easily obtained under mild reaction conditions after the removal of the directing group.

NNN Pincer Ru(II)-Complex-Catalyzed α-Alkylation of Ketones with Alcohols.

A series of novel ruthenium(II) complexes supported by a symmetrical NNN ligand were prepared and fully characterized. These complexes exhibited good performance in transfer hydrogenation to form new C-C bonds using alcohols as the alkylating agents, generating water as the only byproduct. A broad range of substrates, including (hetero)aryl- or alkyl-ketones and alcohols, were well tolerated under the optimized conditions.

Iodine-Mediated Difunctionalization of Imidazopyridines with Sodium Sulfinates: Synthesis of Sulfones and Sulfides.

Novel iodine-induced sulfonylation and sulfenylation of imidazopyridines have been described using sodium sulfinates as the sulfur source. This strategy enables highly selective difunctionalization of imidazo[1,2-a]pyridine to access sulfones and sulfides in good yields. A wide range of substrates and functional groups were well-tolerated under optimized conditions.

Rhodium-Catalyzed Direct Bis-cyanation of Arylimidazo[1,2-α]pyridine via Double C-H Activation.

An efficient Cp*Rh(III)-catalyzed selective bis-cyanation of arylimidazo[1,2-α]pyridines with N-cyano-N-phenyl-p-methylbenzenesulfonamide via N-directed ortho double C-H activation has been developed. The reaction proceeds with broad functional group tolerance to furnish various cyanated imidazopyridines in high yields. The current methodology exhibits unique characteristics, including high bis-cyanation selectivity, operational convenience, and gram-scale production.

Cobalt(II)-Catalyzed Oxidative C-H Arylation of Indoles and Boronic Acids.

Co(II)-catalyzed C-H C2 selective arylation of indoles with boronic acids through monodentate chelation assistance has been achieved for the first time. The unique features of this methodology include mild reaction conditions, highly C2 regioselectivity, and employment of a Grignard reagent-free catalytic system. A wide range of substrates, including unreactive arenes, are well tolerated, which enables the construction of the coupling products efficiently.

Mixed Directing-Group Strategy: Oxidative C-H/C-H Bond Arylation of Unactivated Arenes by Cobalt Catalysis.

A mixed directing-group strategy for inexpensive [Co(acac) ]-catalyzed oxidative C-H/C-H bond arylation of unactivated arenes has been disclosed. This strategy enables the arylation of a wide range of benzamide and arylpyridines effectively to afford novel bifunctionalized biaryls, which are difficult to achieve by common synthetic routes. Two different pathways, namely, a single-electron-transmetalation process (8-aminoquinoline-directed) and a concerted metalation-deprotonation process (pyridine-directed), were involved to activate two different inert aromatic C-H bonds.