New Copper(I) oxide biocatalyst based on functionalized olive stone for the synthesis of 1,4-disubstituted-1,2,3-triazoles under very mild conditions

An efficient methodology for coating silanized olive stone with copper(I) oxide has been described and fully characterized using various techniques, including X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR-ATR), X-ray fluorescence (XRF), electronic microscopy, thermogravimetric analysis (TGA), moisture content, electrophoretic mobility and particle size distribution. The applicability of this new biocatalyst in the 1,3-dipolar cycloaddition click reaction between alkynes and azides has been demonstrated leading to the obtention of a great variety of 1,4-disubstituted-1,2,3-triazoles with good to excellent conversions. The new biocatalyst showed promising features in terms of recyclability and industrial or biomedical application. It could be recycled up to five times with minimal loss of catalytic activity when synthezing compound 3a-3n. Additionally, it was effective in the multi-gram scale synthesis of compounds 3b and 3e, which were tested for the first time in cells, specifically on the human fibroblast-derived M1 cell line, demonstrating that these compounds are non-cytotoxic and thus suitable for potential uses in biomedicine.