Direct synthesis, postsynthetic modification, and chiral induction have been recognized as three powerful methods to synthesize chiral covalent organic frameworks (CCOFs). However, catalytic asymmetric methodology, as the most important and effective synthetic approach to access chiral organics, has not been enabled for CCOFs synthesis thus far. Herein we report, for the first time, the construction of CCOFs from prochiral monomers via catalytic asymmetric polymerization. The obtained propargylamine-linked CCOFs can be the highly reusable chiral catalysts to promote asymmetric Michael addition reactions. The concept of catalytic asymmetric polymerization might open a new route for constructing the CCOFs that are not possible with the existing CCOF synthetic methods.

A novel covalent organic framework material COF-DM, which contains chelating coordination environments, was synthesized at the gram level under mild conditions. In addition, its Cu­(II)-loaded complex of Cu­(II)@COF-DM was prepared by impregnating COF-DM in an acetonitrile solution of CuCl2 via a solid-state coordination approach. The obtained Cu­(II)-loaded Cu­(II)@COF-DM can be used as a highly active heterogeneous catalyst to catalyze the alkyne-dihalomethane-amine coupling reactions.

The content of sulfur dioxide derivatives in cells is closely related to life and health. Therefore, it is essential to detect the content of sulfur dioxide derivatives in cells under physiological conditions to ensure life and health. In this paper, a novel sulfur dioxide derivative fluorescent water-soluble probe ((E)-1,1,3-trimethyl-2-(2-(naphthalen-1-yl)vinyl)-1H-3λ 4-benzo[e]indole, TNB) was synthesized by using naphthalene formaldehyde (1) and 1,1,2,3-tetramethyl-1H-3λ 4benzo[e] indole (2) as raw materials. Based on the intramolecular charge transfer (ICT) mechanism of the naphthalene ring to benzoindole, TNB exhibits very weak fluorescence emission in PBS buffer (pH 7.4). The olefin unit of TNB can be combined with HSO3-/SO3 2with high selectivity to make the π-π conjugate interrupt. ICT is blocked, TNB produces a strong fluorescence emission, and the color visible to the naked eye changes from yellow to colorless. The effect of TNB on HSO3-/SO3 2can be completed in 40 s, the fluorescence intensity is increased by 91 times, and the detection limit is as low as 0.089 μM. It is expected to be able to rapidly detect low levels of sulfur dioxide derivatives in cells, which has important application prospects in maintaining life and health.

Ozone is widely used in daily life, but studies have shown that O3 can damage human trachea and lungs, leading to diseases such as asthma, emphysema, and bronchitis. Therefore, it is of great significance to develop a simple and efficient detection method for monitoring O3 in living cells. In this study, 3-(but-3-en-1-yl)-2-(7-(but-3-en-1-yloxy)-2-oxo-2H-chromen-3-yl)benzo[d]thiazol-3-ium (BCT) as a new type of water-soluble fluorescent probe was synthesized by substitution reaction of 4-bromo-1-butene and hydroxycoumarin-benzothiazole derivatives, which can specifically detect ozone in aqueous solution. The interaction of ozone on the probe can be completed within 20 min, the fluorescence intensity is significantly enhanced, and it has the advantages of high sensitivity (detection limit LOD = 43 nM). The influence of pH on the fluorescent performance of BCT shows that the probe with super stability under weak alkali and acidic environment, which provides the necessary conditions for its detection of ozone in physiological system detection. Therefore, BCT is expected to become an effective tool for detecting ozone in cellular organisms.