Eight chelating resins were synthesized in high yields by supporting 2‐aminomethylpyridine, 2,2′‐dipyridylamine, 1,2‐phenylenediamine and 1,2‐ethylenediamine on Merrifield and Wang resins, respectively. These resins were used both as support of reducing complexes and as alkali metal sensors. 16 stable and easy to prepare reducing complexes, derived from the chelating resins and LiBH4 and NaBH4, were prepared in good yields. These complexes showed chemoselectivity to reduce aldehydes in a low molar ratio and short time reactions. The fluorescence‐sensing behavior of the chelating resins for alkali metal was studied. The fluorescence response of the materials where 1, 2‐phenylenediamine is supported on Merrifield and Wang resins indicate that they behave as sensors for Li+and K+, respectively.