Developing green-safe, efficient and recyclable catalysts is crucial for the chemical industry. So far, organic photocatalysis has been proved to be an environmentally friendly and energy-efficient synthetic technology compared with traditional metal catalysis. As a versatile catalytic platform, hyper-crosslinked polymers (HCPs) with large surface area and high stability are easily prepared. In this report, we successfully constructed two porous HCP photocatalysts (TZ-HCPs) featuring s-tetrazine units and surface areas larger than 700 m2 g−1 through Friedel–Crafts alkylation reactions. The rational energy-band structures and coexisting micro- and mesopores endow TZ-HCPs with excellent activities to realize the green synthesis of benzimidazoles (28 examples, up to 99% yield, 0.5–4.0 h) in ethanol. Furthermore, at least 21 iterative catalytic runs mediated by TZ-HCP1D were performed efficiently, with 96–99% yield. This study of TZ-HCPs sheds light on the wide-ranging prospects of application of HCPs as metal-free and green photocatalysts for the preparation of fine chemicals.
22 October 2010 in Bioorganic & Medicinal Chemistry Letters
A versatile and environmentally friendly method for the synthesis of various organophosphorus compounds have been developed under microware conditions. We have synthesized a series of the trifluoromethyl phosphonates via Phospha-Brook rearrangement between dialkylphosphite and 3-(trifluoroacetyl)coumarins using KF/Al2O3 as a highly efficient solid catalyst under solventless conditions. Catalyst reuse, ease of separation of the pure product, and high yields are some of the unique features of this process. In addition, the mycelial growth rate method was used to examine the in vitro antifungal activities of the phosphates 4a-o against Phytophthora capsici, Fusarium oxysporum vasinfectum, Bipolaris maydis and Alternaria solani at 500 µg/mL. The results showed that compound 4n exhibited significant anti-Phytophthora capsici activity with inhibitory index of 86%.
Herein, quinazolinone-based TICT-type AIEgens were developed, converting ACQ to AIE. They exhibit strong blue emission, long phosphorescence lifetimes, and lipid-activated response, enabling high-resolution multilevel fingerprint imaging.
Rhodanine and its derivatives have been known as privileged structures in pharmacological research because of their wide spectrum of biological activities, but the synthesis method of rhodanine skeleton is limited. In this paper, not only rhodanine skeleton, but also N-aryl rhodanines can be directly prepared via the reaction of thioureas and thioglycolic acid in one step catalyzed by protic acid, which provides a new approach of the synthesis of rhodanine and its derivatives. The developed strategy is straightforward, efficient, atom economical, and convenient in good yields.
31 October 2023 in Organic & Biomolecular Chemistry
A novel C–N coupling of arylamines with dialkyl azodicarboxylates under metal-free conditions for the rapid assembly of carbamates has been achieved. The synthetic application of products was exemplified by several intriguing chemical operations.