Palladium-Catalyzed 1,2-Alkynylarylation of Vinyl Arenes with Haloalkynes and Arylboronic Acids

We herein disclose a novel palladium-catalyzed 1,2-alkynylarylation of vinyl arenes using haloalkynes and arylboronic acids as coupling partners. This reaction is characterized by broad substrate scope, controllable reaction sequence, and excellent chemo- and regioselectivities. Mechanistic investigations suggest that the reaction is initiated by regioselective insertion of vinyl arenes into the alkynyl-Pd(II) species, and the silver salt is crucial for this transformation, serving as both the Lewis acid and halide scavenger. This protocol provides efficient access to new carbon skeletons, which are embedded in the key biologically active motifs

Controllable <i>O</i>‑Nucleometalation Cyclization Strategy: Access to Divergent Ring-Functionalized Molecules

The vinyl moiety-assisted selective <i>O</i>-nucleopalladation is reported, which offers rapid constructions of cycloolefins and cyclopropanes via oxidant-induced cyclization of enynes. O₂ resulted in the unexpected 6-<i>endo</i>-Heck cyclization, while CuCl₂ led to a 5-<i>exo-trig</i> pathway and synergetic S_N2-type C–C bond formation. Amide works as an <i>O</i>-transferred nucleophilic group to activate the alkyne moiety, which induced divergent annulation processes. Moreover, the regenerated amides could be used for further modifications

Receiver operating characteristic for the present algorithm when the training set of LTAFDB database is applied with threshold values from 0.0 to 1.0 in increments of 0.001.

<p>The calculated value for the area under the blue curve is 0.9845.</p

Pd(II)-Catalyzed Sequential C–C/C–O Bond Formations: A New Strategy to Construct Trisubstituted Furans

Palladium-catalyzed oxidative difunctionalization of enol ethers with 1,3-dicarbonyl compounds to construct trisubstituted furans in one step under mild conditions is described. The reaction is thought to proceed through a C–C bond formation along with a C–O bond closing the ring structure. Oxygen is the sole oxidant regenerating the Pd(II) catalyst

Palladium-Catalyzed Oxidative Carbonylation for the Synthesis of Polycyclic Aromatic Hydrocarbons (PAHs)

A direct and facile palladium-catalyzed C–H bond oxidative carbonylation reaction and oxidative cyclization for the synthesis of polycyclic aromatic hydrocarbons (PAHs) is reported herein. The intramolecular cyclocarbonylation, through C–H activation and C–C, C–O bond formations under mild conditions, proceeds smoothly with good functional group tolerance in high to excellent yields. The intramolecular palladium-catalyzed direct oxidative C–H bond functionalization for the C–O bond formation is also demonstrated, which provides an efficient approach for the construction of various PAHs

Palladium-Catalyzed Intermolecular Dehydrogenative Aminohalogenation of Alkenes under Molecular Oxygen: An Approach to Brominated Enamines

A novel and efficient palladium-catalyzed dehydrogenative aminohalogenation of alkenes with molecular oxygen as the sole oxidant has been developed. This protocol provides a valuable synthetic tool for the assembly of a wide range of brominated enamines under mild conditions, with unprecedented stereoselectivity and exceptional functional group tolerance. This attractive route for the synthesis of brominated enamines is of great significance due to the products’ versatile reactivity for further transformations

Base-Mediated Three-Component Tandem Reactions for the Synthesis of Multisubstituted Pyrimidines

A base-mediated three-component tandem reaction for the synthesis of multisubstituted pyrimidines from amidines, aryl alkynes, and aldehydes in a one-pot manner has been developed. Advantages of this transformation include being transition-metal-free, high efficiency, available starting materials, and being environmentally friendly

Palladium-Catalyzed Oxidative Annulation of Acrylic Acid and Amide with Alkynes: A Practical Route to Synthesize α‑Pyrones and Pyridones

A range of internal alkynes smoothly underwent palladium-catalyzed oxidative annulations with acrylic acid and amide to afford α-pyrones and pyridones in good to excellent yields with high regioselectivity. The usage of O₂ (1 atm) as a stoichiometric oxidant with H₂O as the only byproduct under mild conditions makes this process more attractive and practical

Overview of the beat-by-beat AF detection algorithm.

<p>Overview of the beat-by-beat AF detection algorithm.</p

Probability histogram for annotated AF and non-AF beats of AFDB set.

<p>Probability histogram for annotated AF and non-AF beats of AFDB set.</p