Pd(OAc)-Catalyzed Approach to Phenanthridin-6(5)-one Skeletons.

Herein, we present a Pd(OAc)/Dppp-catalyzed synthesis of 4-arylphenanthridinones from 2-bromobenzamides and iodobenzene, which undergoes successive Ullman cross-coupling, C-H activation, and oxidative coupling dehydrogenation process. The presented methods offer an adaptable and modular synthesis route for efficiently producing a wide array of valuable phenanthridiones, demonstrating exceptional compatibility with functional groups. Alternatively, a 1:1 cross-coupling reaction utilizing an intramolecular norbornene moiety as the ligand resulted in phenanthridinones through -arylation and C-H activation.

Pd(OAc)-Catalyzed Synthesis of Imidazo[1,2-]phenanthridines via a Sequential Ullmann Coupling and Oxidative Coupling Dehydrogenation.

The Ullmann coupling and oxidative coupling dehydrogenation reactions have occurred sequentially, catalyzed by Pd(OAc), which unexpectedly yielded fused imidazo[1,2-]phenanthridine derivatives in good to high yields. Structural analysis of the intermediate and final products indicated that the protocol did not include C-H and N-H arylation.

Access to Carbonyl Azides via Iodine(III)-Mediated Cross-Coupling.

Herein, we present a prominent metal-free C-N cross-coupling platform that enables access to carbamoyl- and ketoazides from isocyanides or silyl enol ethers and trimethylsilyl azide (TMSN) with an aid of iodine(III) promoter. This offers a rapid route to a diverse set of synthetically valuable azide decorated fragments with excellent substrate scope and good to excellent yields. The disclosed platform exemplifies the use of TMSN for incorporation of the azide fragment without the loss of N.

Silver-Catalyzed Radical Umpolung Cross-Coupling of Silyl Enol Ethers with Activated Methylene Compounds: Access to Diverse Tricarbonyl Derivatives.

A silver-catalyzed protocol for the intermolecular radical umpolung cross-coupling protocol of silyl enol ethers with activated methylene compounds is disclosed. The protocol exhibits excellent functional group tolerance, enabling the expedient preparation of a variety of tricarbonyl compounds. Preliminary mechanistic investigations suggest that the reaction proceeds through a process involving free radicals in which silver oxide has a dual role, acting as both a catalyst and a base.

Copper-Catalyzed Decarboxylation Cross-Coupling Cascade Reaction for Synthesis of Fused Dihydro-benzoxazinones.

A protocol for a tandem copper-catalyzed intermolecular decarboxylation cross-coupling cascade between -bromobenzoic acids and proline or piperic acid has been disclosed. The developed protocol allows access to a variety of synthetically useful fused benzoxazinones scaffolds with high efficiency and good functional group compatibility. A mechanistically sequential approach for the decarboxylation and dehydration coupling process was presented.

General Approach to Amides through Decarboxylative Radical Cross-Coupling of Carboxylic Acids and Isocyanides.

Herein, we report a silver-catalyzed protocol for decarboxylative cross-coupling between carboxylic acids and isocyanides, leading to linear amide products through a free-radical mechanism. The disclosed approach provides a general entry to a variety of decorated amides, accommodating a diverse array of radical precursors, including aryl, heteroaryl, alkynyl, alkenyl, and alkyl carboxylic acids. Notably, the protocol proved to be efficient for decarboxylative late-stage functionalization of several elaborate pharmaceuticals, demonstrating its potential applications.

Synthesis of pyrimidine-fused skeletons through copper-catalyzed consecutive Sonogashira coupling and aminocyclization.

A copper-catalyzed sequence involving a Sonogashira coupling reaction and 5- aminocyclization between a terminal alkyne and a 2-(2-bromophenyl)pyrimidine analog based on six-membered rings is presented. This protocol provides a controlled and modular approach to access a variety of synthetically useful pyrimidine-fused skeletons with high efficiency, broad substrate scope, and excellent functional group compatibility. Under acidic conditions, the ()-configuration of products spontaneously converts into ()-9-benzylidene-1,9-dihydro-11-pyrazolo[4',3':4,5]pyrimido[2,1-]isoindol-11-ones.

Construction of Phenanthridinone Skeletons through Palladium-Catalyzed Annulation.

Herein, a straightforward synthetic approach for the construction of phenanthridin-6(5)-one skeletons is disclosed. The developed protocol relies on palladium catalysis, providing controlled access to a range of functionalized phenanthridin-6(5)-ones in 59-88% yields. Furthermore, plausible reaction pathways are proposed based on mechanistic experiments.

Copper-Catalyzed Consecutive Ullmann, Decarboxylation, Oxidation, and Dehydration Reaction for Synthesis of Pyrrolo or Pyrido[1,2-]imidazo[1,2-]quinazolines.

A protocol for a copper-catalyzed intermolecular cross-coupling cascade between 2-(2-bromoaryl)-1-benzo[]imidazole analogues and proline or pipecolic acid has been developed. The developed protocol allows access to a variety of synthetically useful -fused pyrrolo or pyrido[1,2-]imidazo[1,2-]quinazoline scaffolds with high efficiency and good functional group compatibility. Proline or pipecolic acid plays a dual role in the reaction: as ligand and reactants.

[Anti-fatigue effect of Lubian on kidney Yin deficiency and kidney Yang deficiency mice and mechanism based on PI3K-Akt pathway].

This study aimed to investigate the anti-fatigue effect and mechanism of Lubian(Cervi Penis et Testis) on kidney Yin deficiency and kidney Yang deficiency mice. After one week of adaptive feeding, 88 healthy male Kunming mice were randomly divided into a blank group, a kidney Yin deficiency model group, a kidney Yin deficiency-Panacis Quinquefolii Radix(PQR) group, kidney Yin deficiency-Lubian treatment groups, a kidney Yang deficiency model group, a kidney Yang deficiency-Ginseng Radix et Rhizoma(GR) group, and kidney Yang deficiency-Lubian treatment groups, with eight mice in each group. The kidney Yin deficiency model and kidney Yang deficiency model were prepared by daily regular oral administration of dexamethasone acetate and hydrocortisone, respectively, and meanwhile, corresponding drugs were provided.

Tandem Palladium/Copper-Catalyzed Decarboxylative Approach to Benzoimidazo- and Imidazophenanthridine Skeletons.

A protocol for a tandem Pd/Cu-catalyzed intermolecular cross-coupling cascade between -bromobenzoic acids and 2-(2-bromoaryl)-1-benzo[]imidazoles or the corresponding imidazoles is presented. The protocol provides conceptually novel and controlled access to synthetically useful -fused (benzo)imidazophenanthridine scaffolds with high efficiency, a broad substrate scope, and excellent functional group compatibility.

Silver-Catalyzed Controlled Intermolecular Cross-Coupling of Silyl Enol Ethers: Scalable Access to 1,4-Diketones.

A protocol for silver-catalyzed controlled intermolecular cross-coupling of silyl enolates is disclosed. The protocol displays good functional group tolerance and allows efficient preparation of a series of synthetically useful 1,4-diketones. Preliminary mechanistic investigations suggest that the reaction proceeds through a one-electron process involving free radical species in which PhBr acts as the oxidant.

A rearrangement of saccharin-derived cyclic ketimines with 3-chlorooxindoles leading to spiro-1,3-benzothiazine oxindoles.

An unusual rearrangement of saccharin-derived cyclic ketimines (SDCIs) and 3-chlorooxindoles has been developed to provide a series of spiro-1,3-benzothiazine oxindoles. The reaction features simple manipulations, short reaction times, mild reaction conditions and inexpensive reagents. It is the first example where SDCIs serve as a ring-opening reagent in organic synthesis.

Silver-Promoted (4 + 1) Annulation of Isocyanoacetates with Alkylpyridinium Salts: Divergent Regioselective Synthesis of 1,2-Disubstituted Indolizines.

An unprecedented silver-promoted regioselective (4 + 1) annulation of isocyanoacetates with pyridinium salts is reported. The established protocol provides controlled, facile, and modular access to a range of synthetically useful N-fused heterocyclic scaffolds containing indolizines, pyrrolo[1,2-]quinolines, pyrrolo[2,1-]isoquinolines, and 1-imidazo[4,5-]indolizin-2(3)-ones. A mechanistic pathway involving nucleophilic addition/protonation/elimination/cycloisomerization is proposed.

Modular synthesis of 3-substituted isocoumarins silver-catalyzed aerobic oxidation/ heterocyclization of -alkynylbenzaldehydes.

A method involving silver-catalyzed aerobic oxidation/6-endo heterocyclization of ortho-alkynylbenzaldehydes to yield 3-substituted isocoumarins is described. The developed protocol allows convenient access to a range of synthetically useful 3-substituted isocoumarins and related fused heterocyclolactones in good to high yields, using silver tetrafluoroborate as the catalyst, and atmospheric oxygen as the terminal oxidant and the source of endocyclic oxygen. Mechanistic studies suggest the involvement of a free-radical pathway.

Synthesis of Sulfonylated Heterocycles via Copper-Catalyzed Heteroaromatization/Sulfonyl Transfer of Propargylic Alcohols.

An unprecedented copper-catalyzed heteroaromatization/sulfonyl transfer of propargylic alcohols with isocyanide has been developed. 3-Sulfonyl benzofurans and indoles were produced under Cu(I) catalysis in good to high yields. The developed catalytic methodology provides controlled, modular, and facile access to sulfonyl benzoheterocycle scaffolds.

Switchable Copper-Catalyzed Approach to Benzodithiole, Benzothiaselenole, and Dibenzodithiocine Skeletons.

A copper-catalyzed reaction between 2-bromo-benzothioamides and S or Se involving sulfur rearrangement is reported, enabling access to benzodithioles and benzothiaselenoles in the presence of CsCO. In the absence of S or Se, the reaction affords dibenzodithiocines via two consecutive C(sp)-S Ullmann couplings.

CuBr-Catalyzed α-Arylation and Aerobic Oxidative Dehydrogenative C-N Coupling for the Synthesis of Spiro[cyclohexane-1,12'-isoindolo[1,2-]quinazolin]-10'-one Derivatives.

A copper-catalyzed approach was disclosed for C(sp)-C(sp) bond formation via an α-arylation of carbonyl, and the subsequent oxidative dehydrogenation coupling occurred to form a C(sp)-N bond, wherein O served as a green oxidant. This protocol provided a domino method for the synthesis of spiro[cyclohexane-1,12'-isoindolo[1,2-]quinazolin]-10'-ones containing a nitrogen-substituted quaternary carbon center.

Silver-Assisted [3 + 2] Annulation of Nitrones with Isocyanides: Synthesis of 2,3,4-Trisubstituted 1,2,4-Oxadiazolidin-5-ones.

A silver-assisted method for [3 + 2] annulation of nitrones with isocyanides has been developed. The developed protocol allows access to a variety of 2,3,4-trisubstituted 1,2,4-oxadiazolidin-5-one derivatives as single diastereomers in good to excellent yields using silver oxide as the catalyst and molecular oxygen as the terminal oxidant. A plausible mechanism involving a nucleophilic addition/cyclization/protodeargentation/oxidation pathway is proposed on the basis of experimental results.

Silver-Mediated Synthesis of Substituted Benzofuran- and Indole-Pyrroles via Sequential Reaction of -Alkynylaromatics with Methylene Isocyanides.

A silver-mediated reaction between 2-ethynyl-3-(1-hydroxyprop-2-yn-1-yl)phenols or 2-ethynyl-3-(1-hydroxyprop-2-yn-1-yl)anilines and methylene isocyanides has been developed. A sequential 5-- cyclization and [3 + 2] cycloaddition process is proposed. This synthetic strategy is atom- and step-efficient and applicable to a broad scope of substrates, allowing the synthesis of valuable substituted benzofuran- and indole-pyrroles in moderate to high yields.

[3 + 2] Cycloaddition of Isocyanides with Aryl Diazonium Salts: Catalyst-Dependent Regioselective Synthesis of 1,3- and 1,5-Disubstituted 1,2,4-Triazoles.

An unprecedented catalyst-dependent regioselective [3 + 2] cycloaddition of isocyanides with aryl diazonium salts is reported. 1,3-Disubstituted 1,2,4-triazoles were selectively obtained in high yield under Ag(I) catalysis, whereas 1,5-disubstituted 1,2,4-triazoles were formed by Cu(II) catalysis. These catalytic methodologies provide a controlled, modular, and facile access to 1,2,4-triazole scaffolds with high efficiency, broad substrate scope, and excellent functional group compatibility.

Dioxane-involving reaction for the synthesis of 3-aryl-1-(2-(vinyloxy)ethoxy)isoquinolines catalyzed by AgOTf.

Dioxane was found to be involved in the reaction of 2-(arylethynyl)benzaldehydes and 3-aminopyrazine-2-carbohydrazide, and underwent a ring-opening reaction catalyzed by AgOTf. This domino type procedure provided an efficient method for the synthesis of 3-aryl-1-(2-(vinyloxy)ethoxy)isoquinolines in good yields via the loss of a molecule of 3-aminopyrazine-2-carboxamide.

Synthesis of Substituted 4 H-Thiochromen-4-imines via Copper-Catalyzed Cyclization Cascades of o-Bromobenzothioamides with Terminal Alkynes.

A series of ( E)- N-aryl-4 H-thiochromen-4-imines has been conveniently obtained through a cascade reaction between o-bromobenzothioamides and terminal alkynes. This novel approach probably involved an initial generation of benzothietane-2-imine intermidates via an intramolecular Ullmann reaction under CuI/L-proline cocatalysis and alkaline conditions followed by imine alkynylation, ring opening, and cyclization sequences to provide the unexpected 4 H-thiochromen-4-imines rather than isothiochromans.

An efficient synthesis of 16H-dibenzo[2,3:6,7][1,4]oxazepino[5,4-b]quinazolin-16-ones via an Ullmann reaction catalyzed by CuI.

CuI functions as a mild Lewis acid catalyst to promote the condensation and cyclization reaction of 2-amino-N-(2-hydroxyphenyl)benzamide and 2-bromobenzaldehyde to build the quinazoline moiety first. With the addition of CsCO, it also can catalyse the subsequent intramolecular Ullmann type reaction to give 16H-dibenzo[2,3:6,7][1,4]oxazepino[5,4-b]quinazolin-16-ones in good yields.