Deoxygenation of Ethers To Form Carbon–Carbon Bonds via Nickel Catalysis

In this article a successful protocol was developed to construct carbon–carbon bonds by the extrusion of the O atom of ethers via nickel catalysis in the presence of reductants. This methodology is featured as a highly economic route to construct sp³–sp³ C–C bonds through dual C–O activation of ethers with good functional group tolerance

Palladium-Catalyzed Direct Annulation of Benzoic Acids with Phenols to Synthesize Dibenzopyranones

Direct annulation of benzoic acids with phenols via palladium-catalyzed oxidative coupling is reported. Readily available and inexpensive starting materials were used in this novel method to synthesize highly valuable and useful dibenzopyranone scaffolds. Broad substrate scope and simple operation make this method potentially practical. Preliminary mechanistic studies were conducted to understand this chemistry and inspire new designs of oxidative coupling of different functionalized arenes

C–O/C–H Coupling of Polyfluoroarenes with Aryl Carbamates by Cooperative Ni/Cu Catalysis

Cross-coupling of polyfluoroarenes with aryl carbamates through the cleavage of both sp² C–O and C–H bonds is reported. The reaction conditions are simple, and only transition-metal catalysts and ligands are essential. Mechanistic studies indicated that Ni catalyst played an important role in activating C–O bond, while the Cu one in activating C–H Bond. The developed system proved to be effective for cross-coupling of terminal alkynes with aryl carbamates

Olefinic C–H Bond Addition to Aryl Aldehyde and Its <i>N</i>‑Sulfonylimine <i>via</i> Rh Catalysis

The first example of olefinic C–H addition to <i>N</i>-sulfonylaldimines and aryl aldehydes is reported. This strategy offered a concise and high atom-economic approach to vinyl amines and vinyl alcohols

Silver-Catalyzed Long-Distance Aryl Migration from Carbon Center to Nitrogen Center

Selective cleavage of an inert C–C bond followed by C–O/N bond formation through a long-distance aryl migration from a carbon to a nitrogen center via Ag catalysis is reported. The migration products were easily converted into γ-hydroxy amines and tetrahydro­quinoline derivatives in quantitative yields. Preliminary mechanistic studies indicated a radical pathway

Direct Lactonization of 2‑Arylacetic Acids through Pd(II)-Catalyzed C–H Activation/C–O Formation

Palladium-catalyzed direct lactonization of 2-arylacetic acids through a reaction sequence that includes C–H activation/C–O formation is reported. This method provides a concise and efficient pathway to synthesize fully functionalized benzofuranone derivatives, which are highly relevant to bioactive natural and synthetic products

Mechanistic Insight into the Regioselective Palladation of Indole Derivatives: Tetranuclear Indolyl Palladacycles with High C2–Pd or C3–Pd Bond Selectivity

This research provides a straightforward understanding of the regioselective palladation of indole derivatives by capturing both C2–Pd and C3–Pd intermediates of <i>N</i>-phenylindole and <i>N</i>-methylindole. Those tetranuclear indolyl palladacycles suggest that the regioselectivity of palladation depends on the N-substituted protective groups of indoles as well as the acidity of the reaction medium

Fe-Promoted Chlorobenzylation of Terminal Alkynes through Benzylic C(sp³)–H Bond Functionalization

A chlorobenzylation of terminal alkynes through Fe­(II)-promoted benzylic C­(sp³)–H bond functionalization in the presence of NCS as a chloride source was developed. Compared with previous methods to prepare polysubstituted alkenyl halides, the presented procedure provides an efficient alternative with high atom and step economy under mild conditions. The transformation was established to proceed through a single-electron transfer (SET) process with benzyl cations as key intermediates

Synthesis of Fluorenone Derivatives through Pd-Catalyzed Dehydrogenative Cyclization

Palladium-catalyzed dual C–H functionalization of benzophenones to form fluorenones by oxidative dehydrogenative cyclization is reported. This method provides a concise and effective route toward the synthesis of fluorenone derivatives, which shows outstanding functional group compatibility

<i>N</i>-Directing Group Assisted Rhodium-Catalyzed Aryl C–H Addition to Aryl Aldehydes

Direct aryl C–H addition to aryl aldehydes to produce biaryl methanols was reported <i>via</i> Rh catalysis with an <i>N</i>-containing directing group. The method is highly atom-, step-, and redox-economic. The procedure is robust, reliable, and compatible with water and air