From a first iteration of the deconvolution procedure, all compounds in the candidate library were predicted to be present in the NMR spectrum in greater proportion than the threshold value of 5%. The HMCMC fitting of these spectra resulted in predicted relative concentrations that closely match the true values (Fig. ). The model predicted the compo- This example further highlights a key aspect of fitting spectra via HMCMC: in regions where spectral peaks heavily overlap, the chemical shift predictions become less precise. This imprecision in chemical shift fitting primarily results from the broadening step. As described above, broadening the spectrum increases the gradient information used by the fitting algorithm. The broadening, however, widens the line shapes and results in a loss of resolution in the sharp peaks and splitting patterns, which reduces sensitivity to precise chemical shift positions. It's worth noting, however, that even with this broadening step, the fitting process can provide accurate predictions of relative concentrations, as long as the chemical shifts are approximately in the correct positions. In the next example, we analyzed NMR spectra of the crude reaction mixture resulting from the borylation of C-H bonds of aromatic compounds (Fig. ). The borylation of picoline (2a) could occur at any of the arene C-H bonds (2b-e) or at the benzylic C-H bond (2f ).