In this work, we report the microwave‐assisted synthesis of six new pentacoordinate and chiral organotin compounds (1–6) derived from amino acid based Schiff bases. The syntheses were achieved through multicomponent reactions (MCRs) of l‐amino acids (tryptophan, tyrosine, and phenylalanine), 2‐hydroxy‐1‐naphthaldehyde, and the corresponding diorganotin oxide (R2SnO, R = nBu or Ph). These compounds were characterized by NMR spectroscopy (1H, 13C, and 119Sn), HRMS, UV/Vis spectroscopy, and fluorescence spectroscopy. All of the compounds in solution exhibited fluorescence with quantum yields (Φ) in the range 0.08 to 0.21. The cytotoxicities of 1–6 at 0.1 µg mL–1 were investigated, and they are practically harmless to melanoma B16F10 cells. The fluorescent staining ability of the organotin compounds toward silk fibroin was investigated by the immersion method and analyzed by confocal microscopy, which showed the efficient and uniform integration of the luminescent compounds. DFT calculations of the interactions of a truncated organotin–fibroin complex are also reported.

The fluorescent silk fibroin (FSF) is useful in a number of biomedical applications.

Five novel organoboron complexes were synthesized in just 15 min via microware irradiation, by one pot multicomponent reactions between diverse aryl aldehydes with benzoylhydrazide, or 4-nitrobenzoylhidrazine and diphenyl boronic acid, in a 1:1:1 ratio in benzene. The products were characterized by 1 H, 13 C, 11 B NMR, UV, IR, spectroscopy and high-resolution mass spectrometry (HRMS). The molecular structure was also determined by singlecrystal X-ray diffraction for two complexes, which showed the tetra-coordination of the boron atoms giving rise to distorted tetrahedral molecular geometry with a strong intermolecular C-H···π interactions. In spite of the low quantum yields exhibited by the series in solution, some complexes stained uniformly the silk fibroins emitting enough fluorescence to allow its characterization by confocal microscopy. Boron as chelate center of the five complexes resulted not to be toxic for B16F10 cells, these compounds are appropriate for their used in medical applications.

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