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Herein, we disclosed a highly chemoselective synthesis of quinoline-2-one and quinoline-2-thione derivatives using EtOS 2 K as the C1 source. Quinoline-2-one derivatives were synthesized selectively with NaCl as a catalyst in the solvent DMSO/H 2 O, while quinoline-2-thione derivatives were produced without the need for any catalyst in an environmentally friendly solvent EtOH/H 2 O. The reaction conditions were mild and had good functional group tolerance.

This report describes the use of a simple Pd/NBE catalytic system to achieve ortho C-H oxylation and phosphonylation and other functionalizations of aryl iodide through templated conversion reactions. Dimethylamine is introduced in the ortho -site of aryl iodide through C-H amination, and aryl dimethylamine is quickly converted to methyl quaternary ammonium salt precipitation. Methyl quaternary ammonium salt avoids Hofmann elimination in subsequent functionalization. This method solves various ortho functionalization reactions of aryl iodide that have not been achieved for a long time in the field of Pd/NBE chemistry indirectly.

We report a cathodic reduction-dominated electrochemical approach for the hydrogenation of azobenzenes in dichloromethane. With cheap and readily available N , N -diisopropylethylamine as a catalytic mediator, the reaction proceeded smoothly in a simple undivided cell under constant-current electrolysis. A series of azobenzenes were successfully reduced to the corresponding hydrazobenzenes in moderate to high yields at room temperature. Preliminarily mechanistic studies indicate that solvent dichloromethane acts as a hydrogen source. The use of a common solvent as a hydrogen source, no need for stoichiometric mediators or metallic reductants, and mild conditions make this work a more straightforward and sustainable protocol for hydrogenation of azobenzenes.

The free radical cyclization reaction is a promising strategy for ring framework formation. Herein, we report a copper-catalyzed tandem radical cyclization strategy for preparing substituted lactam derivatives. This reaction proceeds through a radical coupling approach, which not only allows a wide range of alkenes but also is quite compatible with the primary, secondary, and tertiary radicals. In addition, density functional theory calculations were performed to gain insights into the reaction mechanism.

An iron(II)-catalyzed bisphosphorylation cascade cycloisomerization of readily accessible γ-hydroxyl ynones and diphenylphosphine oxides is described. This strategy provides a variety of valuable polysubstituted bisphosphorylated dihydrofuran scaffolds via the construction of two C-P bonds and one C-O bond within a single procedure. This developed reaction system demonstrates good functional group compatibilities with considerably low catalyst consumption (as low as 1%), which could be further scaled up to gram quantities in satisfactory yields.

This report developed a method for the synthesis of C8-aminated pyrrolo-phenanthridines or -indoles by series ortho C(sp 2 )-H amination/ ipso C(sp 2 )-H or C(sp 3 )-H arylation. N-benzoyloxyamines, as electrophilic amination reagents, did not undergo an electrophilic substitution reaction with the pyrrole side, but they did undergo a site-selective C-H amination reaction with the benzene side via Pd/NBE catalysis. The C8-aminated pyrrolo-phenanthridines have strong fluorescence in solution and solid state. X-ray single crystal diffraction shows that the steric hindrance of amino and ortho benzene ring may inhibit aggregation-caused quenching (ACQ).

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.

A AgSCF 3 /Na 2 S 2 O 8 -promoted trifluoromethylthiolation/cascade cyclization of o-propargyl arylazides (or o-alkynyl benzylazides) triggered by a carbon-carbon triple bond is reported. This strategy provides the synthesis of valuable SCF 3 -substituted quinoline and isoquinoline systems via the construction of one C(sp 2 )-SCF 3 bond and one C-N bond within one process.

A Mannich reaction of imines and ketones induced by persistent radical cation salts was investigated, and a series of Mannich bases, beta-aminoketones, were synthesized. A novel cyclization to form the 4-piperidone skeleton was achieved in a tandem process. The reaction can be rationalized as a radical cation process supported by various evidence.