The chemo-selective synthesis of Nsulfonyl amidines is realized via the decomposition of the enamine C=C bond of enaminoesters through an in situ generated triazoline intermediate. Control experiments prove that the electron withdrawing ester group in the enamine component is crucial in inducing the chemo-selective formation of amidines. The method is featured with high efficiency and sustainability by employing pure water as medium without requiring any catalyst or additive. Scheme 1. Different reaction pathways between enamines/ enamine precursors and azide.

Owing to their excellent photoelectric properties, perovskite materials have broad application prospects; however, the toxicity of Pb limits the application of Pb‐based perovskite materials. To overcome this problem, Pb‐free perovskite materials are prepared by replacing Pb with nontoxic elements including Ge and Sn; nevertheless, the stabilities of these materials are low. Herein, single crystals of nontoxic Cu(I)‐based ternary metal halide (Cs3Cu2Br5) with outstanding stabilities and self‐trapped excition (STE) emission are constructed by an antisolvent method for the first time; these crystals exhibit central blue emission at 458 nm and large Stokes shifts. Photoluminescence (PL) intensities of the single crystals remain above 96.9% of their initial intensities when these crystals are exposed to an atmospheric environment for 90 days. Moreover, the stabilities of the Cs3Cu2Br5 single crystals are investigated by temperature‐dependent PL spectroscopy, which suggests a considerable exciton binding energy of 503 meV, and derivative thermogravimetric analysis, which indicate that the temperature of complete decomposition of Cs3Cu2Br5 is above 930 °C. Furthermore, a new class of white light‐emitting diodes with an ultrahigh color rendering index of 97.8 and satisfactory performance is produced using the Cs3Cu2Br5 single crystals. The study demonstrates significant potentials of Cu(I)‐based single crystals in the field of optoelectronics.

The zero‐dimensional perovskite‐like derivative Cs3Cu2X5 (X = Cl, Br, I) with self‐trapped excitons (STEs) photoluminescence (PL) has attracted tremendous interest in the field of optoelectronics. Nonetheless, it is challenging for Cs3Cu2Br5 material to attain full visible spectrum emission and prevent light‐induced photochemical damage to the retina (blue light hazard) in applications. Herein, Mn2+ is chosen as the dopant to alloy into Cs3Cu2X5 via a one‐step solid state synthesis method. Significantly, the series of Mn2+‐doped show the emission peak of 460 nm STEs and the emission peak of 550 nm Mn2+. More importantly, the high energy absorption of Mn2+ facilitates the transfer of exciton energy, contributing to a reduction in blue emission peak at 460 nm. Simultaneously, ≈17.5% of Mn2+ is alloyed into the Cs3Cu2X5lattice to induce the energy transfer channels from the Cs3Cu2X5 host to the Mn2+ guest to lead to the emission of Mn2+, which broadens emission spectrum (400–620 nm) and realizes 80% reduction of the blue emission peak at 460 nm. Additionally, a white light‐emitting diodes can decrease the blue emission band via 71.45% and an ultrahigh color rendering index (CRI) of 94.5 is produced using the 17.5% Mn2+: Cs3Cu2X5 perovskite‐like derivative powder material.

Due to the special gem-nitrogen structure, amidines are important compounds in the synthesis of nitrogen contaning products. As a class of featured amidines, the N-sulfonyl amidines are key intermediates in a number of pivatol organic syntheses, and thus ocuppy significant position in modern organic synthesis. In this context, the research advances on the synthesis of N-sulfonyl amidines are herein reviewed. Based on the key reaction features, the introduction covers the synthetic methods of enamination by tertiary enamine oxidation, amide activation, akyne-azide-amine three-component reaction, enamine carbon-carbon bond functionalization and other related reactions. It is expected that this review will provide guidelines for the reasearch work in related areas.

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