Polymer-Supported Fe-Phthalocyanine Derived Heterogeneous Photo-Catalyst for the Synthesis of Tetrazoles Under Visible Light Irradiation

Herein, a polymer supported Fe-Phthalocyanine entangled with carboxyl functionalized benzimidazolium moiety (PSFePcCFBM) explored as heterogenous photocatalyst, for regioselective synthesis of 1H-tetrazoles from sodium azide and other affordable substrates. The PSFePcCFBM displayed good to excellent yield of the product (79-91%) under visible light (5 W) irradiations using home-made photoreactor. The NaN3 acts as a nitrogen donor of tetrazoles ring as well as it convert aldehyde into isocyanide as one of the nitrogen sources. The catalyst could be recycled up to 5th run successfully without altering its catalytic activity. The small amount of the catalyst loading, extensive substrate range, ease of separation of the catalyst by simple filtration, less reaction time, simple workup procedure, and excellent product yield are the salient features of the investigated protocol.

Automated summary

In this study, a polymer supported Fe-Phthalocyanine catalyst (PSFePcCFBM) was utilized for the regioselective synthesis of 1H-tetrazoles, achieving yields ranging from 79-91%. The catalyst could be recycled up to 5 times without losing its activity, and the protocol offered features such as low catalyst loading, broad substrate range, easy catalyst separation, short reaction time, simple workup procedure, and high product yield.