Ultrathin organic polymer with p-πconjugated structure for simultaneous photocatalytic disulfide bond generation and CO_(2)reduction

Combining photocatalytic organic reactions with CO_(2)reduction is an efficient solar energy utilization mode,but it is still limited by the organic species that can be matched and the low conversion.Herein,ultrathin organic polymer with p-πconjugated structure(TPP)was rationally designed and prepared,and showed a high yield of CO(15.2 mmol g^(-1))and conversion of SAS coupled products(100%),far exceeding the organic polymer with P=O structure.The enhanced photoredox activity of TPP is ascribed to the orbital interaction between the p-orbital on phosphorus and theπ-orbitals of aromatic,which can accelerate the photoinduced charge carrier separation and improve the CO_(2)adsorption capacity.TPP can also be used for the dehydrocoupling of various benzyl mercaptans to the corresponding SAS bond products.This work provides a new concept for the efficient synthesis of disulfide bonds combined with CO_(2)reduction in a photoreaction system.

Synthesis of biheteroaryls via 2-methyl quinoline C(sp^(3))-H functionalization under metal-free conditions

An acetic acid-promoted C(sp^(3))-H functionalization of 2-methyl quinoline,enaminoesters and elemental sulfur for the synthesis of 3,4,5-trisubstituted isothiazoles under metal-free conditions has been developed.This approach provides viable access to various 5-(quinolin-2-yl)isothiazoles in moderate to good yields with good functional group tolerance.Moreover,the success of the gram-scale reaction gives this reaction a great potential application.

Diverse catalytic systems for nitrogen-heterocycle formation from O-acyl ketoximes

O-Acyl ketoximes has been proven to be versatile building blocks for practical construction of Nheterocycles.In the last few years,diverse catalytic systems have been discovered to enable efficient transformations of O-acyl ketoximes to a range of nitrogen-heterocycles.Herein,we summarized our recent examples of novel nitrogen-heterocycle formation with new function findings of O-acyl ketoximes through facile aerobic copper catalysis,metal-free N–O bond activation,multi-component assembly,and bis-annulations.From the green chemistry perspective,these works represent efficient methods with high atom economy,high selectivity,and minimized chemical waste.These findings also complement well to the previous mainly copper-based catalytic systems and more importantly enrich the oxime chemistry in organic synthesis.

Electrosynthesis of Azobenzenes Directly from Nitrobenzenes

The electrochemical reduction strategy of nitrobenzenes is developed.The chemistry occurs under ambient conditions.The protocol uses inert electrodes and the solvent,DMSO,plays a dual role as a reducing agent.Its synthetic value has been demonstrated by the highly efficient synthesis of symmetric,unsymmetric and cyclic azo compounds.

Copper-Catalyzed Aerobic Oxidative Ring Expansion of Isatins: A Facile Entry to Isoquinolino-Fused Quinazolinones

A copper-catalyzed aerobic oxidative ring expansion reaction of isatins with 1,2,3,4-tetrahydroisoquinoline for the synthesis of tetra-cyclic quinazolinones has been developed.This reaction is performed smoothly under simple conditions to give the corresponding products in moderate to good yields with good functional group tolerance.

Metal-Free Synthesis of Benzo[a]phenanthridines from Aromatic Aldehydes,Cyclohexanones,and Aromatic Amines

A three-component synthesis of benzo[a]phenanthridines from aromatic aldehydes,cyclohexanones,and aromatic amines has been developed,which is mediated by KI/DMSO/camphorsulfonic acid to afford a variety of functionalized benzo[a]phenanthridines in satisfactory yields.The present strategy provides a biaryl motif ortho to the nitrogen atom which has the potential to be used as ligand by further modification.With the advantages of readily available starting materials,transition-metal-free conditions,gram-scale synthesis,and broad substrate scope,this three-component protocol provides an efficient approach for the preparation of diverse benzo[a]phenanthridines.

Three-Component Synthesis of 2-Heteroaryl-3-hydroxybenzo[b]- thiophenes under Transition-Metal-Free Conditions

A convenient synthetic route to 2-heteroaryl-3-hydroxybenzo[b]thiophene derivatives via K_(2)CO_(3)-promoted multicomponent cycliza-tion between o-halogenated benzaldehyde,2-methylquinolines and sulfur powder has been demonstrated.This reaction is performed smoothly under simple conditions to give the corresponding products in moderate to good yields.The resultant 3-hydroxybenzo[b]thiophenes have been proved to be versatile building blocks in a range of transition-metal-catalyzed cross-coupling reactions.

Visible-light-driven Cadogan reaction

Visible-light-driven photochemical Cadogan-type cyclization has been discovered.The organic D-A type photosensitizer 4 CzIPN found to be an efficient mediator to transfer energy from photons to the transient intermediate that breaks the barriers of deoxygenation in Cadogan reaction and enables a mild metalfree access to carbazoles and related heterocycles.DFT calculation results indicate mildly endergonic formation of the intermediate complex of nitrobiarenes and PPh3,which corresponds with experimental findings regarding reaction temperature.The robust synthetic capacity of the photoredox Cadogan reaction systems has been demonstrated by the viable productivity of a broad range of carbazoles and related N-heterocycles with good tolerance of various functionalities.

Cu-Catalyzed Cascade Cyclization of Ketoxime Acetates and Alkynals Enabling Synthesis of Acylpyrroles

A facile copper-based catalytic system has been developed to enable efficient cyclization of methylketoximes and alkynals.This protocol provides a viable entry to synthetically and pharmaceutically useful 2-acylpyrroles with a broad range of compatible functionalities.Mechanistically,a key acyl migration is probably involved that leads to the formation of N-acyl pyrroles or otherwise NH pyrroles by further hydrolysis.More importantly,the present reaction system also gives an opportunity to realize three-component pyrrole assembly by simple addition of carboxylic acid.

Rhodium(III)-catalyzed successive C(sp^(2))-H and C(sp^(2))-C(sp^(2))bond activation of aryl oximes:synthetic and mechanistic studies

Merging selective C-H cleavage with C-C cleavage in a tandem reaction has been a practical strategy that permits skeletal diversification from simple raw materials.Herein,we describe a rhodium(III)-catalyzed redox-neutral reaction of aryl oximes and internal alkynes to generate novel N-(2-cyanoaryl)indanone imines.

Iron-catalyzed indolo[2,3-c]quinoline synthesis from nitroarenes and benzylic alcohols/aldehydes promoted by elemental sulfur

An iron-catalyzed strategy for the rapid synthesis of indolo[2,3-c]quinolines has been developed.This cascade reaction involving alcohol oxidation,nitro reduction,and oxidative annulation was achieved in a one-pot.The present protocol was started from mono-functionalized indoles and readily available benzylic alcohols/aldehydes,affording a variety of functionalized indolo[2,3-c]quinolines in satisfactory yields.

Metal-Free Synthesis of 2-Aminobenzothiazoles via I2-Catalyzed Tandem Cyclization Reaction of Amines and Carbon Disulfide

Comprehensive Summary,A convenient approach for the construction of 2-aminobenzothiazoles via I2-catalyzed tandem cyclization reaction of amines and carbon disulfide has been developed.The present approach starts from simple and readily available starting materials,affording a series of 2-aminobenzothiazoles in up to 89%yields under metal-free conditions.In this work,C—H/N—H functionalization was achieved and multiple C-hetero bonds were successfully constructed in one pot.