Tailoring a Polyoxometalate-Based Metal–Organic Framework for Photocatalytic Oxidative Cross-Coupling Reactions to Synthesize Benzo(naphtho)thiazoles

Benzo(naphtho)thiazoles and their derivatives are widely used in optoelectronic materials, medicinal chemistry, and industry. Visible-light-induced photocatalytic cross-dehydrogenative coupling (CDC) reactions have emerged as a green and efficient alternative, but existing catalytic systems still suffer from limitations such as the high cost of precious metal catalysts, poor stability of organic-based catalysts, and low bond-formation efficiency. Herein, a photoactive polyoxometalate-based metal–organic framework (POMOF) catalyst, [Cu 2 (BTIz) 3 (H 2 O) 5 SiW 12 O 40 ]·5H 2 O ( CuW– BTIz, BTIz = 4,7-bis(imidazolyl) benzothiazole), was synthesized by integrating the electron-acceptor polyanion [SiW 12 O 40 ] 4– into a BTIz -based MOF. BTIz serves as a donor–acceptor–donor photosensitizer with extended visible-light absorption and efficient electron transfer capability, while [SiW 12 O 40 ] 4– acts as an electron trap to promote charge separation via coordination interactions. Under white light irradiation at room temperature, CuW–BTIz exhibits excellent performance in the CDC reactions for synthesizing benzo(naphtho)thiazoles, achieving moderate-to-high yields. This work provides a promising heterogeneous photocatalytic strategy for the green and efficient synthesis of benzo(naphtho)thiazole derivatives.