Copper-bonded polyoxomolybdates-based framework as a heterogeneous catalyst for the cascade click reaction and bromination.

• CPF-1 is based on (Mo 6 O 20) n isopolyoxomolybdate chains bonded together with CuO 4 tetrahedra into a 3D inorganic polymer. • CPF-1 has high stability and excellent heterogeneous catalytic activity, the synthesis of alkynes into bromotriazole with ∼99 % yield. • The possible cascade catalytic mechanisms of the click and bromination reactions catalyzed by CPF-1 were also proposed. The selective conversion of alkynes into bromotriazoles over a single-component catalyst is highly desirable but presents significant challenges. In this study, we developed a robust copper-bonded polyoxomolybdates-based framework [Cu 2 (Mo 6 O 20)]·2H 2 O (CPF-1), and it integrates the catalytic ability of Cu(I) site with the multielectron-transfer ability of polyoxometalates. As a result, CPF-1 exhibits favorable bifunctional catalytic activity for click chemistry and achieves 99% yield in the conversion of corresponding products to bromotriazoles. To our knowledge, CPF-1 represents the first heterogeneous catalyst that significantly enhances cascade reaction with excellent efficiency and sustainable recyclability. Additionally, the possible cascade catalytic mechanisms of these two reactions are also proposed. The copper-bonded polyoxomolybdates-based framework (CPF-1) exhibits highly efficient heterogeneous catalytic activities in tandem click and bromination reactions (yields of up to 99 %). Furthermore, CPF-1 can be easily recovered and reused without significant loss of activity after seven reaction cycles. [Display omitted] [ABSTRACT FROM AUTHOR]