Paper-Based Colorimetric Sensor System for High-Throughput Screening of C−H Borylation.

A paper-based colorimetric sensor system (PBCSS) was developed to detect the amount of bis(pinacolato)diboron (B₂Pin₂) and applied as a high-throughput screening protocol in Ir-catalyzed C−H borylation. First, 96 ligands were screened for the borylation of benzene, and then 12 of them were selected and tested for five substrates. These reaction mixtures were spotted in the PBCSS, showing a blue-violet color. The value of the gray scale of each reaction was obtained from these colored spots and converted to the extent of conversion of B₂Pin₂. The extents of conversion of B₂Pin₂ obtained from the PBCSS showed good correlation with those obtained from gas chromatography analysis. In addition, the modified conversion using blank data showed good correlation with the yield of products. [ABSTRACT FROM AUTHOR]