Visible-Light-Mediated Three-Component Alkene 1,2-Alkylpyridylation Reaction Using Alkylboronic Acids as Radical Precursors for the Synthesis of 4-Alkylpyridines.

We report the photocatalyzed three-component alkene 1,2-alkylpyridylation reaction between alkylboronic acids, 4-cyanopyridine, and an olefin to achieve the pyridination and alkylation of the olefin and the synthesis of structurally diversified 4-alkylpyridines. The readily available and easily manipulated alkylboronic acids were used as alkyl radical precursors. The reactions take place under mild conditions with a broad substrate scope and are easy to scale up to gram level, and they are therefore of potential practical value for the synthesis and structural modification of biologically active alkylpyridine derivatives.

A Theoretical Study of Positively Curved Circulenes Embedded with Five-Membered Heterocycles: Structures and Inversions.

Recently, polycyclic arenes with positive curvature have gained increasing significance in the field of material chemistry. This study specifically explores the inversion barriers of a series of positively curved circulenes by using five-membered heterocycles integrated into the backbone of primitive [5]circulenes and [6]circulenes. For hetero[5]circulenes, where one benzenoid ring is replaced by a heterocycle, the inversion barriers exhibit a strong correlation with the rotary angles of the heterocycles, and larger rotary angles result in lower inversion barriers.

Visible-Light-Mediated Three-Component Decarboxylative Coupling Reactions for the Synthesis of 4-Alkylpyridines.

4-Alkylation of pyridines has been achieved by a photocatalyzed three-component reaction of an olefin, an aryloxyacetic acid, and cyanopyridine using Ir[dF(CF)ppy](dtbbpy)PF as a photocatalyst. In this way, a new type of 4-alkylpyridines bearing aryl and aryloxy substituents on the phenyl was accessed with potential pharmaceutical value. In addition to mild reaction conditions, the method has several other advantages, including a multicomponent one-pot protocol, good functional group tolerance, and easy amplification of the reaction scale.

Azopyridine Aqueous Electrochemistry Enables Superior Organic AZIBs.

Azo compounds (AZO), such as azobenzene, are classic organic electrode materials featuring a redox potential close to Zn/Zn. Recent studies show that azobenzene could work as a cathode in aqueous zinc-ion batteries (AZIBs), providing a voltage output of around 0.7 V.

Theoretical Study on Vibrationally Resolved Electronic Spectra of Chiral Nanographenes.

Nanographenes are of increasing importance owing to their potential applications in the photoelectronic field. Meanwhile, recent studies have primarily focused on the pure electronic spectra of nanographenes, which have been found to be inadequate for describing the experimental spectra that contain vibronic progressions. In this study, we focused on the vibronic effect on the electronic transition of a range of chiral nanographenes, especially in the low-energy regions with distinct vibronic progressions, using theoretical calculations.

Site-selective α-C(sp)-H arylation of dialkylamines via hydrogen atom transfer catalysis-enabled radical aryl migration.

Site-selective C(sp)-H arylation is an appealing strategy to synthesize complex arene structures but remains a challenge facing synthetic chemists. Here we report the use of photoredox-mediated hydrogen atom transfer (HAT) catalysis to accomplish the site-selective α-C(sp)-H arylation of dialkylamine-derived ureas through 1,4-radical aryl migration, by which a wide array of benzylamine motifs can be incorporated to the medicinally relevant systems in the late-stage installation steps. In contrast to previous efforts, this C-H arylation protocol exhibits specific site-selectivity, proforming predominantly on sterically more-hindered secondary and tertiary α-amino carbon centers, while the C-H functionalization of sterically less-hindered N-methyl group can be effectively circumvented in most cases.