Copper-mediated intramolecular C(sp)-H amination of alicyclic amines: regio- and site-selective access to imidazolidin-4-one.

An efficient copper-mediated intramolecular C(sp)-H amination of alicyclic amine is developed. This amination protocol is performed under mild reaction conditions by using di--butyl peroxide (DTBP) as the oxidant, exhibiting a wide range of functional group tolerance and affording regio-selective products in up to 89% yield. Preliminary mechanistic studies indicated that a Cu(I)/Cu(III) reaction model is most likely to be involved in this C-H amination reaction.

Recent developments in the utilization of pyridones as privileged scaffolds in drug discovery.

Introduction: Pyridones are six-membered, nitrogen-containing heterocycles, possessing two isomeric forms; these are 2-pyridones and 4-pyridones. Both pyridone rings display unique physicochemical properties including weak alkalinity and dual hydrogen-bond donor/acceptor propensities. These heterocyclic compounds are particularly underlined for their diverse biological effects, including their cytotoxicity activity as well as their antibacterial, antiviral, anti-inflammatory, and anti-fibrotic properties.

Electrochemically Driven Chalcogenative Cyclization of 2-Alkynyl Aryl Oxime: Access to Functionalized Isoquinolines.

A transition-metal-free electrochemical chalcogenative cyclization of 2-alkynyl aryl oxime with dichalcogenides has been established to assemble valuable 4-organochalcogen isoquinolines concisely. This protocol proceeds via constant electrolysis in a user-friendly undivided cell setup. It circumvents the necessity of transition metal catalysts, chemical oxidants, and harsh reaction conditions.

Transition-Metal-Free Electrochemical Selenylative Cyclization of Alkynyl Phosphonates.

Unprecedented regioselective electrochemical tandem selenation/cyclization of alkynyl phosphonates with diselenide is described here. These obtained selenoether products can be chemo-selectively converted into halogen-functionalized cyclic enol phosphonates under our electrochemical conditions. These protocols provide straightforward access to valuable cyclic enol phosphonate or phosphaisocoumarins under the electrochemical and transition-metal-free conditions.

Palladium-catalyzed distal selective C-H chalcogenation of biphenyl amines.

A palladium-catalyzed distal C(sp)-H chalcogenation of biphenyl amines is described. This protocol demonstrates scalability, excellent chemo- and regio-selectivity, and broad functional group tolerance, providing efficient access to valuable aryl chalcogenides. Notably, the chalcogenated biphenyl amines could be further transformed to 8-membered N, Se(S)-heterocycles through copper-catalyzed intramolecular C-N cyclization.

Ar-turmerone suppresses Aspergillus flavus growth and aflatoxin accumulation: Finding a new antifungal agent based on stored maize.

Aspergillus flavus (A. flavus) is a common saprophytic pathogenic fungus that produces toxic and carcinogenic aflatoxins prone to contaminate food. Here, we optimized the synthesis method of Ar-turmerone, the main active ingredient in turmeric essential oil, improved its yield and reduced the operation requirements.

Redox-neutral rhodium(III)-catalyzed divergent synthesis of tetrasubstituted 1,3-enynes and alkynylated benzofurans.

With the assistance of the acetamido directing group (DG), a rhodium-catalyzed C-H alkenylation/DG migration cascade for the synthesis of tetrasubstituted 1,3-enynes from -phenoxyacetamides and 1,3-diynes has been achieved in this work. Alternatively, a rhodium-catalyzed [3 + 2] annulation for the synthesis of alkynylated benzofurans from the same set of substrates has also been achieved by simply changing the reaction conditions. This work highlights the tunable divergent synthesis of valuable compounds triggered by C-H activation.

Electrochemical selenium-π-acid promoted hydration of alkynyl phosphonates.

An unprecedented electrochemical selenium-π-acid promoted hydration of internal alkynes bearing a phosphonate auxiliary was described. Thus, valuable (hetero)aryl and alkyl ketones could be accessed under mild, metal- and external oxidant-free conditions. This protocol features high atom-economy, good chemo- and regio-selectivity, excellent functional group tolerance and easily transformable products.

Hydroxyl-Directed Ruthenium-Catalyzed -Selective C-H Acylmethylation and Annulation of Naphthols with Sulfoxonium Ylides.

Herein, we report a highly efficient ruthenium-catalyzed -selective C(sp)-H acylmethylation of 1-naphthols with α-carbonyl sulfoxonium ylides by utilizing hydroxyl as a weakly coordinating directing group. This new method imparts good reactivity, excellent chemo- and regioselectivity, and broad functional group tolerance and involves mild reaction conditions. The C-H acylmethylated products can be readily cyclized into fluorescent annulated pyrans by a one-pot process.

Y(OTf)-catalyzed phosphorylation of 2H-chromene hemiacetals with P(O)-H compounds to 2-phosphorylated 2H-chromenes.

A facile synthesis of 2-phosphorylated 2H-chromenes has been accomplished herein via a Y(OTf)-catalyzed dehydrative coupling of 2H-chromene hemiacetals with P(O)-H compounds. This protocol features low catalyst loading, mild reaction conditions, broad substrate scope and easy elaboration of the products.

Copper-mediated oxidative C-H/N-H activations with alkynes by removable hydrazides.

The efficient copper-mediated oxidative C-H alkynylation of benzhydrazides was accomplished with terminal alkynes. Thus, a heteroaromatic removable -2-pyridylhydrazide allowed for domino C-H/N-H functionalization. The approach featured remarkable functional group compatibility and ample substrate scope.

Novel synthesis of divergent aryl imidazoles from ketones involving copper-catalyzed α-amination and oxidative C-C bond cleavage.

A one-pot synthesis, initiated by a copper salt with inorganic (NH)CO as the nitrogen source, forms divergent aryl imidazole derivatives from ketones α-amination and oxidative C-C bond cleavage reactions. The approach provides a simple and rapid synthesis of imidazole derivatives and has certain versatility.

Ruthenium Catalyzed C-H Selenylations of Aryl Acetic Amides and Esters via Weak Coordination.

An efficient ruthenium-catalyzed direct C-H selenylation of aryl acetic amides and esters has been achieved via distal weakly coordination. Notable features of this protocol including broad substrate scope, wide functional group tolerance, and good regioselectivity. In addition, diaryl disulfides were also successfully applied to this reaction under slightly modified conditions.

Copper salt-catalyzed formation of a novel series of triazole-spirodienone conjugates with potent anticancer activity.

Copper salt-catalyzed oxidative amination resulted in the formation of a novel series of triazole- spirodienone conjugates, 4-triazolyl-1-oxa-4-azaspiro[4,5]deca-6,9-dien-3,8-diones and 4-triazolyl-1-oxa-4-azaspiro[4,5]deca-6,9-dien-8-ones. A single crystal of compound among them was grown and analyzed by X-ray crystallography. These compounds were evaluated for their antiproliferative activities against MDA-MB-231, HeLa, A549 and MCF-7 cell lines.