Photoexcited nitroarenes for alkylation of quinoxalin-2(1)-ones.

A straightforward method for the dehydrogenative alkylation of quinoxalin-2(1)-ones with alkylbenzenes has been developed, facilitated by a photoexcited nitroarene. The reaction's success hinges on the dual role of the photoexcited nitroarene molecule, acting as both a hydrogen atom transfer (HAT) reagent and an oxidant. This technique is both atom-economical and cost-effective, due to the readily available nitroarene, which serves as the sole intermediary in the reaction process.

Lewis base-catalyzed cascade [4 + 2]-annulation reaction of -alkoxy acrylamides and acyl isothiocyanates: facile access to 2-imino-1,3-thiazinone derivatives.

A formal [4 + 2]-cycloaddition reaction of -alkoxy acrylamides and acyl isothiocyanates was developed a Lewis base-catalyzed cascade aza-nucleophilic addition/thio-Michael addition process under mild conditions. This study provides a facile approach for preparing 2-imino-1,3-thiazinone derivatives in moderate to excellent yields and enriches the field of heterocyclic acrylamide chemistry. The reported method features metal-free reaction conditions, high atom economy, and easy operation.

Synthesis of Polycyclic Imidazolidinones via Cascade [3 + 2]-Annulation of β-Oxo-acrylamides with Cyclic -Sulfonyl Imines.

An EtN-catalyzed cascade [3 + 2]-annulation of β-oxo-acrylamides with cyclic -sulfonyl ketimines or sulfamate-derived imines is developed under mild reaction conditions, which provides a concise and efficient route to access valuable sultam- or sulfamidate-fused imidazolidinone derivatives in good to excellent yields (80-95% yields) with excellent diastereoselectivities (>20:1 drs). The current protocol features atom economy, a transition-metal-free process, and broad functional group tolerance. Moreover, the asymmetric variant of the [3 + 2]-cycloaddition reaction was achieved in the presence of diphenylethanediamine or quinine-based bifunctional squaramide organocatalysts and , giving the corresponding chiral polycyclic imidazolidinones in 68-90% yields with 25-94% ees and >20:1 drs in all cases.

Boosting the output performance of triboelectric nanogenerators surface engineering and structure designing.

Triboelectric nanogenerators (TENGs) have been utilized in a wide range of applications, including smart wearable devices, self-powered sensors, energy harvesting, and high-voltage power sources. The surface morphology and structure of TENGs play a critical role in their output performance. In this review, we analyze the working mechanism of TENGs with the aim to improve their output performance and systematically summarize the morphological engineering and structural design strategies for TENGs.

Organocatalytic cascade nucleophilic/aza-Michael addition reactions: metal-free catalytic strategy for the synthesis of hydantoins.

Lewis base-catalyzed cascade nucleophilic/aza-Michael addition reaction of -alkoxy β-oxo-acrylamides with isocyanates has been developed to afford various highly functionalized hydantoin derivatives in 80-98% yields under mild reaction conditions. The intriguing features of this method include metal-free reaction conditions, low catalyst loading, broad substrate scope and short reaction time.

Photoelectric properties of aromatic triangular tri-palladium complexes and their catalytic applications in the Suzuki-Miyaura coupling reaction.

The photoelectric properties and catalytic activities of substituted triphenylphosphine and sulfur/selenium ligand supported aromatic triangular tri-palladium complexes 1-4, abbreviated as [Pd], were investigated. The cyclic voltammogram of [Pd] in CHCN-BuNPF showed a single quasi-reversible wave which was consistent with their robust property and provided preliminary proof for their electron transfer processes in catalysis. With excitation at 267 nm, [Pd] exhibited strong ratiometric fluorescence at 550 and 780 nm at a temperature gradient from 77 K to 287 K.

Visible-light-induced dearomative oxamination of indole derivatives and dearomative amidation of phenol derivatives.

Herein, we report a protocol for visible-light-induced dearomative oxamination reactions of indole derivatives to afford functionalized spirocyclic products. These step-economical reactions, which involve C-N and C-O bond formation, feature mild conditions, a broad substrate scope, high yields, exclusive diastereoselectivity and step-economy. In addition, a similar protocol could be used to synthesize spirolactams by dearomative amidation of phenol derivatives.

Visible-light-induced intramolecular sp C-H oxidation of 2-alkyl-substituted benzamides for the synthesis of functionalized iminoisobenzofurans.

We have developed a protocol for the synthesis of functionalized iminoisobenzofurans by means of visible-light-induced intramolecular cyclization reactions of 2-alkyl-substituted benzamides. This one step-economical protocol, which involves intramolecular sp3 C-O bond formation, features mild reaction conditions, exclusive chemoselectivity, and high yields.

NIS-mediated oxidative arene C(sp)-H amidation toward 3,4-dihydro-2(1H)-quinolinone, phenanthridone, and N-fused spirolactam derivatives.

A new radical-mediated intramolecular arene C(sp2)-H amidation of 3-phenylpropanamides or [1,1'-biphenyl]-2-carboxamides was developed to prepare a series of 3,4-dihydro-2(1H)-quinolinone and phenanthridone derivatives in moderate to excellent yields (33-94%). Spirolactams could also be obtained using this protocol.

Enantioselective Conjugate Addition of 2-Acetyl Azaarenes to β,β-Disubstituted Nitroalkene for the Construction of All-Carbon Quaternary Stereocenters.

The first highly enantioselective conjugate addition of 2-acetyl azaarenes to α-substituted-β-nitroacrylates was successfully realized under mild conditions by a Ni(II)-bisoxazoline complex, providing the desired adducts bearing an all-carbon quaternary stereocenter in high yield with excellent enantioselectivity. The products obtained in this system could be readily converted into optically active β-amino esters, succinates, lactones, and lactams.