94866-88-3

Upstream product

• 88284-48-4 2-(trimethylsilyl)phenyl trifluoromethanesulfonate 
• 613-45-6 2,4-Dimethoxybenzaldehyde 
• 19434-34-5 2-(phenoxy)benzaldehyde 
• 151-10-0 1,3-Dimethoxybenzene 
• 92-83-1 xanthene 

Relevant academic research and scientific papers

Visible-light induced enhancement in the multi-catalytic activity of sulfated carbon dots for aerobic carbon-carbon bond formation

The development of carbonaceous materials as metal-free catalysts integrating different types of catalysis in a single system represents a significant advance in cascade/tandem organic synthesis. Zero-dimensional carbon dots with tuneable optical properties and easily modifiable surface functionalities can be harnessed as a carbocatalyst for merging photooxidation and acid-catalyzed reactions in one pot. Herein, we explore carbon dots decorated with hydrogen sulfate groups as a photocatalyst for the dehydrogenative cross-coupling of xanthenes with ketones, arenes and 1,3-dicarbonyl compounds that showed high efficiency and selectivity under visible-light irradiation. The sulphated carbon dots demonstrate dual catalytic properties, wherein they induced the rapid photooxidation of xanthenes in the presence of molecular oxygen to form a hydroperoxy intermediate followed by coupling of nucleophiles catalysed by the acidic surface functional groups. The methodology represents an operationally simple pathway for the generation of C-C coupling products in a short reaction time with wide substrate scopes under mild conditions. The catalyst is easily separable and can be reused over multiple cycles with good efficiency.

Graphene-Oxide-Catalyzed Direct CH?CH-Type Cross-Coupling: The Intrinsic Catalytic Activities of Zigzag Edges

The development of graphene oxide (GO)-based materials for C?C cross-coupling represents a significant advance in carbocatalysis. Although GO has been used widely in various catalytic reactions, the scope of reactions reported is quite narrow, and the relationships between the type of functional groups present and the specific activity of the GO are not well understood. Herein, we explore CH?CH-type cross-coupling of xanthenes with arenes using GO as real carbocatalysts, and not as stoichiometric reactants. Mechanistic studies involving molecular analogues, as well as trapped intermediates, were carried out to probe the active sites, which were traced to quinone-type functionalities as well as the zigzag edges in GO materials. GO-catalyzed cross-dehydrogenative coupling is operationally simple, shows reusability over multiple cycles, can be conducted in air, and exhibits good functional group tolerance.

Sulfonic acid-catalyzed autoxidative carbon-carbon coupling reaction under elevated partial pressure of oxygen

An aerobic organocatalytic oxidative C-C bond formation reaction of benzylic C-H bonds with various C-nucleophiles is described. The coupling reaction proceeds by simply stirring the substrates under elevated partial pressure of oxygen in the presence of a sulfonic acid catalyst at room temperature. Elevation of the pressure enables the reaction of a broad scope of nucleophile substrates otherwise showing poor reactivity at ambient pressure. The benzylic C-H bonds of xanthene, acridanes, isochromane and related heterocycles could be functionalized with nucleophiles including ketones, 1,3-dicarbonyl compounds and aldehydes. Electron-rich arenes could be utilized as nucleophiles at elevated temperatures. The reactions are believed to proceed via autoxidation of the benzylic C-H bonds to the hydroperoxides and subsequent nucleophilic substitution catalyzed by sulfonic acids. Copyright

Scandium triflate-catalyzed one-pot domino approach towards general and efficient syntheses of unsymmetrical 9-substituted xanthene derivatives

A general and efficient one-pot cascade/tandem approach to synthesize unsymmetrical 9-aryl/heteroaryl xanthenes has been developed under extremely mild reaction conditions using 10 mol% Sc(OTf)3 as a catalyst. This strategy has been further extended to synthesize 9-(thioaryl) xanthenes through tandem carbon-sulfur (C-S) and carbon-carbon (C-C) bond formation. Novel C-C and C-S bond cleavage promoted by Sc(OTf)3 is also discussed during mechanistic investigation. The Royal Society of Chemistry.

A 2:1 coupling reaction of arynes with aldehydes via o-quinone methides: Straightforward synthesis of 9-arylxanthenes

(Chemical Equation Presented) A novel coupling reaction, where an aldehyde and two molar amounts of an aryne are assembled selectively, has been demonstrated to afford diverse 9-arylxanthene derivatives in one step. o-Quinone methide arising from the [2 + 2] cycloaddition of an aldehyde with an aryne was postulated as a transient intermediate.