Catalyst-dependent oxidative cyclization of diynes with pyridine N-oxides is discovered using an amide directing group. Non-polarized and aminated alkyne could be selectively activated by copper and gold, thus leading to...

An efficient copper-catalyzed oxidative cyclization of diynes is described. A range of functionalized γ-lactams are readily constructed by utilizing this protocol. This copper-catalyzed oxidative process proceeds through alkyne oxidation, carbene/alkyne metathesis, and donor/donor carbene oxidation sequence. The use of readily available substrates, high flexibility, a simple procedure, and mild reaction conditions render it a viable alternative for the preparation of functionalized γ-lactams.

A novel near-infrared (NIR) fluorescent Probe 1 was successfully developed for the reversible detection of sulfur dioxide derivatives and formaldehyde. The purple solution of Probe 1 faded to colorless in 1.8 s with the addition of HSO3 –. Meanwhile, its fluorescence signal disappeared instantaneously with a 39 nM detection limit. The probe exhibited excellent selectivity toward HSO3 – over other potential interfering agents. Then, its absorption and fluorescence bands were able to effectively recover in response to formaldehyde. Remarkably, this reverse process was able to accelerate 84 times under UV light in 122 s and achieved a recovery rate of 98% by UV light, the photoactivation mechanism was fully determined by HRMS and theoretical calculation. Furthermore, we demonstrated that Probe 1 was successfully applied for the detection of sulfur dioxide derivatives and formaldehyde in living cells and data encryption.

Dearomatizing spirocyclization reactions, which are very appealing synthetic strategies to generate functionalized three-dimensional scaffolds from simple two-dimensional precursors. Recently, transition-metal-catalyzed dearomatizing spirocyclization reactions of indolyl ynones has burgeoned, as the construction of synthetically challenging quaternary spirocyclic carbons is easily achieved. In this review, we introduce an overview of advances in the transition-metal-catalyzed dearomatizing spirocyclization reactions of indolyl ynones, and categorize these reactions according to types of catalyst.

Comprehensive Summary A new class of near‐infrared (NIR) fluorescent organoboron AIEgens was successfully developed for latent fingerprints (LFPs) imaging. They exhibit real‐time and in situ high‐resolution imaging performance at 1—3 levels of LFPs by spraying method. In addition, we systematically elucidate the fingerprint imaging mechanism of these AIEgens. Significantly, the excellent level 3 structural imaging capabilities enable the application of them for analyzing incomplete LFPs and identifying individuals in different scenarios.