Crystallization‐induced emission enhancement (CIEE) was demonstrated for the first time for electrochemilunimescence (ECL) with two new benzosiloles. Compared with their solution, the films of the two benzosiloles gave CIEE of 24 and 16 times. The mechanism of the CIEE‐ECL was examined by spooling ECL spectroscopy, X‐ray crystal structure analysis, photoluminescence, and DFT calculations. This CIEE‐ECL system is a complement to the well‐established aggregation‐induced emission enhancement (AIEE) systems. Unique intermolecular interactions are noted in the crystalline chromophore. The first heterogeneous ECL system is established for organic compounds with highly hydrophobic properties.

The GaCl3-catalyzed [4 + 2] cycloaddition between alkoxy- and aryl-activated donor–acceptor cyclobutane diesters and cis-diazene 1a (4-phenyl-1,2,4-triazoline-3,5-dione, PTAD) is disclosed. The reaction provides hexahydropyridazine derivatives as single diastereomers in good to excellent yields in most cases. The structural assignment of the cycloadduct 3b was unambiguously established by single-crystal X-ray diffraction.

Cycloadditions of strained carbocycles promoted by Lewis acids are powerful methods to construct heterocyclic frameworks. In fact, the formal [3+2] cycloadditions of donor-acceptor (DA) cyclopropanes with nitriles has seen particular success in synthesis. In this work, we report on the first [4+2] cycloaddition of nitriles with DA cyclobutanes via Lewis acid activation. Tetrahydropyridine derivatives were obtained in up to 91% yield from various aryl activated cyclobutane diesters and aliphatic or aromatic nitriles.