A novel one-dimensional chain thorium-containing arsenotungstate, H 12 (Th 2 W 3 O 10) (AsW 9 O 33) 2 (H 2 O) 6 ·14H 2 O (Th 2 As 2 W 21), has been successfully synthesized. Th 2 As 2 W 21 consists of a Th 2 W 3 unit that connects two AsW 9 units to form a dimer. Adjacent dimers are linked through two Th–O–W bonds, resulting in an interesting wavy one-dimensional chain. Notably, the incorporation of Th 4+ endows Th 2 As 2 W 21 with remarkable Lewis acidity, enabling it to function as an efficient heterogeneous catalyst for the condensation-cyclization reaction between 2-aminobenzamide and aldehydes to afford 2, 3-dihydroquinazolinones. Under environmentally friendly and mild conditions, a series of 2, 3-dihydroquinazolinones was obtained in excellent yields (up to 98%). This study not only enriches the structural diversity of thorium-containing polyoxometalates but also provides a promising heterogeneous catalyst for the sustainable synthesis of N-heterocycles.
Wu et al. (Sat,) studied this question.