Search

With the development of ortho C-H functionalization in Pd/NBE chemistry, the catalytic systems used are becoming increasingly complex. The increasingly complex catalytic systems may have created technical barri-ers for researchers in other fields to apply Pd/NBE chemical methods. This report describes the use of a simple Pd/NBE catalytic system to achieve ortho C-H oxylation and phosphonylation and other functionalization of iodobenzene through templated conversion reactions. The key point of this method is to explore the previous-ly unknown step of introducing dimethylamine in the ortho position of iodobenzene through C-H amination. Aryl dimethylamine is quickly converted to methyl quaternary ammonium salt precipitation, and methyl qua-ternary ammonium salt effectively avoids Hofmann elimination in the subsequent functionalization.

A novel photoinduced Ru/photocatalyst-cocatalyzed regioselective cross-dehydrogenative coupling of dual remote C–H bonds, including inert γ-C(sp3)–H bonds in amides and meta-C(sp2)–H bonds in arenes, to construct meta-alkylated arenes has been accomplished.

In palladium/norbornene (Pd/NBE) chemistry, the "ortho effect" has been proven to be a key factor in the process of β-carbon elimination to extrude NBE. Herein, we found that the o-iodoaniline protected by a p-methoxybenzenesulfonyl group can recover the "ortho effect" and then undergo N-S bond cleavage with vinyl palladium, thus achieving a highly selective C-N coupling reaction in the Catallani-Lautens reaction system. On the basis of this discovery, a one-step synthesis of highly functionalized tricyclic indole derivatives was realized.

C-aryl glycosides are popular basic skeletons in biochemistry and pharmaceutical chemistry. Herein, ruthenium-catalyzed highly stereo- and site-selective ortho- and meta-C

Free radical cyclization has emerged as one of the most important reaction types, which is widely used in natural product synthesis, pharmaceutical chemistry, and materials science. This report des...

This report describes the first application of a cyclobutanol ring-opening procedure in the Catellani termination reaction, which includes two β-carbon elimination processes. This tandem reaction features mild conditions, high yields, good functional group tolerance, and a broad substrate scope. Meanwhile, four types of electrophiles (N-benzoyloxyamines, alkyl iodides, aryl bromides, and benzyl chlorides) are quite compatible with this termination reaction for the construction of various types of polysubstituted aromatic hydrocarbons.

C-Aryl glycosides are of high value as drug candidates. Here a novel and cost-effective nickel catalyzed ortho-CAr–H glycosylation reaction with high regioselectivity and excellent α-selectivity is described. This method shows great functional group compatibility with various glycosides, showing its synthetic potential. Mechanistic studies indicate that C–H activation could be the rate-determining step.

This report describes palladium-catalyzed C–H glycosylation and retro Diels–Alder tandem reaction via structurally modified norbornadienes (smNBDs). smNBDs were proposed to regulate the reactivity of the aryl-norbornadiene-palladacycle (ANP), including its high chemoselectivity and regioselectivity, which were the key to constructing C2 and C3 unsubstituted C4-glycosidic indoles. The scope of this substrate is extensive; the halogenated six-membered and five-membered glycosides were applied to the reaction smoothly, and N-alkyl (primary, secondary and tertiary) C4-glycosidic indoles can also be obtained by this method. In terms of mechanism, the key ANP intermediates characterized by X-ray single-crystal diffraction and further controlled experiments proved that the migration-insertion of smNBDs with phenylpalladium intermediate endows them with high chemo- and regioselectivity. Finally, density functional theory (DFT) calculation further verified the rationality of the mechanism.

This report describes a palladium-catalyzed dearomatization and amination tandem reaction of 2,3-disubstituted indoles and benzofurans via the Catellani strategy. This reaction provides a new method for the construction of amino-substituted indoline-fused cyclic and benzofuran spiro compounds in good yields. The reaction has broad functional group compatibility and substrate scope.

This report describes a carboxylate-assisted palladium-catalysed Catellani reaction, which is compatible with ortho-amination and unactivated C(sp2)-H arylation. This method was used to synthesize a series of 1-amino substituted dihydrophenanthridines, phenanthridines and 6H-benzo[c]chromenes. Based on kinetic isotope experiments, the kinetic curve proves that pivalic acid accelerates the reaction rate of unactivated C(sp2)-H activation, and thus this rate can keep up with the five membered aryl-norbornene-palladacycle (ANP) intermediate.

Visible-light-induced C–H phosphorylation of para-CAr–H and heteroarenes was realized using cost-effective RuCl3 as a catalyst. The reaction conditions are green and environmentally friendly, using water as a solvent at room temperature and without ligands. A broad range of highly functional organophosphorus compounds were obtained via a cross-dehydrogenation-coupling (CDC) reaction. In addition, we also proved that RuCl3 is a photocatalyst via its absorption spectrum and on/off light experiments.

This report described the first DMAP and PivOH-promoted ortho-C-H amination and ipso-allenization reaction of iodobenzenes realized by Pd/norbornene cooperative catalysis. Based on control experiments and DFT calculations, we speculated that the three ligands have different functions and mechanism paths in the reaction.

This report describes a palladium-catalyzed Catellani reaction consisting of amination/[2 + 3] or [2 + 4] cyclization via a carboxylate ligand-exchange strategy. This method effectively activates

C-Aryl glycosides are of high value as drug candidates. Here a novel and cost-effective nickel catalyzed ortho-CAr-H glycosylation reaction with high regioselectivity and excellent α-selectivity is described. This method shows great functional group compatibility with various glycosides, showing its synthetic potential. Mechanistic studies indicate that C-H activation could be the rate-determining step.

This report describes palladium-catalyzed C–H glycosylation and retro Diels–Alder tandem reaction via structurally modified norbornadienes (smNBDs). smNBDs were proposed to regulate the reactivity of the aryl-norbornadiene-palladacycle (ANP), including its high chemoselectivity and regioselectivity, which were the key to constructing C2 and C3 unsubstituted C4-glycosidic indoles. The scope of this substrate is extensive; the halogenated six-membered and five-membered glycosides were applied to the reaction smoothly, and N-alkyl (primary, secondary and tertiary) C4-glycosidic indoles can also be obtained by this method. In terms of mechanism, the key ANP intermediates characterized by X-ray single-crystal diffraction and further controlled experiments proved that the migration-insertion of smNBDs with phenylpalladium intermediate endows them with high chemo- and regioselectivity. Finally, density functional theory (DFT) calculation further verified the rationality of the mechanism., This report describes palladium-catalyzed C–H glycosylation and retro Diels–Alder tandem reaction via structurally modified norbornadienes (smNBDs).

Multicomponent reactions are fundamentally different from two-component reactions, as multicomponent reactions can enable the efficient and step-economical construction of complex molecular scaffolds from simple precursors. Here, an unprecedented three-component direct C-H addition was achieved in the challenging meta-selective fashion. Fluoroalkyl halides and a wide range of alkenes, including vinylarenes, unactivated alkenes, and internal alkenes, were employed as the coupling partners of arenes in this strategy. The detailed mechanism presented is supported by kinetic isotope studies, radical clock experiments, and density functional theory calculations. Moreover, this strategy provided access to various fluoride-containing bioactive 1,1-diarylalkanes and other challenging synthetically potential products.

Highly functionalized 4-aminoindoles were synthesized via the three-component cross-coupling of o-iodoaniline, N-benzoyloxyamines, and norbornadiene. The Catellani and retro-Diels-Alder strategy was used in this domino process. o-Iodoaniline, with electron-donating and sterically hindered protecting groups, made the reaction selective toward o-C-H amination. On the basis of density functional theory calculations, the intramolecular Buchwald coupling of this reaction underwent a dearomatization and a 1,3-palladium migration process. The reasons for the control of the chemical selectivity by the protecting groups are given. Moreover, synthetic applications toward 4-piperazinylindole and a GOT1 inhibitor were realized.

Application of an oxidative amination reagent (di-tert-butyldiaziridinone) to the Ru3(CO)12-catalyzed ortho-selective CAr–H amination reaction is described. This strategy shows good functional group compatibility with various phenyl-substituted N-heterocycles, including biologically active substrates, thus providing synthetic potential for this methodology. Mechanistic studies showed that the reaction process involves an octahedral ruthenium species, and the carbon monoxide ligand plays a crucial role in the C–H activation.

Herein, a novel photo-induced amine-free radical reductive dehalogenation of inactivated aryl/alkyl bromides and chlorides with a palladium complex is described, which reveals excellent functional group compatibility and broad substrate scope. Extensional transformations for reductive cyclization, dehalogenative deuteration, and intra- and intermolecular radical addition can be achieved smoothly. Mechanistic studies indicate a single-electron photoredox catalytic system with inactivated solvent as the hydrogen atom donor.

Multicomponent reactions can efficiently construct complex molecular structures from simple precursors. Herein, a novel ruthenium-catalyzed three-component highly selective remote C-H functionalization of 8-aminoquinoline amides has been described. The reaction tolerates a wide range of functional groups, producing arylation/difluoroalkylation products of olefins with potential biological activity and pharmaceutical value. Radical scavenging and radical clock experiments show that a free radical process is involved and a H/D exchange experiment suggests that the reaction might involve ortho-C-H activation of the aromatic ring. A possible mechanism is proposed.

This report describes a carboxylate-assisted palladium-catalysed Catellani reaction, which is compatible with ortho-amination and unactivated C(sp

Visible-light-induced C-H phosphorylation of para-C

Multicomponent reactions are fundamentally different from two-component reactions, as multicomponent reactions can enable the efficient and step-economical construction of complex molecular scaffolds from simple precursors. Here, an unprecedented three-component direct C-H addition was achieved in the challenging

Application of an oxidative amination reagent (di-tert-butyldiaziridinone) to the Ru3(CO)12-catalyzed ortho-selective CAr-H amination reaction is described. This strategy shows good functional group compatibility with various phenyl-substituted N-heterocycles, including biologically active substrates, thus providing synthetic potential for this methodology. Mechanistic studies showed that the reaction process involves an octahedral ruthenium species, and the carbon monoxide ligand plays a crucial role in the C-H activation.