A One-Dimensional Thorium-Containing Arsenotungstate for the Synthesis of 2,3-Dihydroquinazolinones

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.