In-situ analysis to investigate photo-catalytic procedures for the formation of Carbon-Oxygen bonds

Nickel-catalyzed dual photoredox/catalyzed cross-coupling reactions are very promising methodologies for C-O bond formation that are very inexpensive and sustainable by coupling nickel catalysts with photocatalysts. However, for electron-rich aromatic substrates, catalyst degradation to metallic "Nickel black" has been observed, resulting in kinetic deactivation. From these results it was required to investigate if such catalyst deactivations are present in previously optimized cross-coupling procedures coupled with different photocatalytic systems, through the "Same Excess Experiment" procedure. This analysis allowed to disprove the presence of possible catalytic deactivations by simple graphical visual observations, obtained from In-Situ monitoring of cross-coupling reactions by FTIR emission spectroscopic analysis.