bonus, the reduced number of equations translates into a reduced number of DFT
values that need to be calculated and, therefore, in a considerable reduction of time
and effort (by a factor of 10 in this case).
It is interesting to note that, for example, under the conditions of some of their
experiments, a fast process, not included in the current mechanisms of Fig. 14,
shows up after about 1,000 s (Fig. 16, solid lines, simulation; dash-dot, experiment).
This may correspond to the time needed to build up a steady state concentration of an
intermediate, like FABÁH2O, that feeds a water-mediated catalytic cycle with rates
and regioselectivities different from those of the Lewis acid catalytic cycle, as
pointed out by Yu et al. In such cases, one can develop and calibrate a starting
model to reproduce the initial stages of the reaction and then add other mechanisms.
In fact, for the training experiments 1, 2, and 11 of this example, we used only the
data points up to 1,000 s. Afterward, the water-mediated and alcohol-mediated
catalytic cycles could be added, as a refinement of the mechanisms already
implemented and calibrated to a first approximation.
90.0
85.0
80.0
75.0
70.0
65.0
60.0
Regioselectivity (%)
55.0
50.0
0
2 0
Regiosel.Fit%
Regiosel.Meas%
FirstGenSel.Fit
FirstGenSel.Meas
40
Epoxide Conversion
60
80
100
50.0
60.0
First-generation selectivity (%)
70.0
80.0
90.0
Experiment 1, fitted
Experim. 20, predicted, +P2
Runs 1 to 21
Runs 1 to 17
100.0
110.0
1.0E–03
1.0E–04
k(1/s)
1.0E–05
80
110.0
100.0
90.0
80.0
70.0
60.0
50.0
79
78
77
76
75
74
73
Regioselectivity (%)
Regioselectivity (%)
First-generation selectivity (%)
72
71
70
0
0
50.0
55.0
60.0
65.0
70.0
75.0
80.0
85.0
90.0
20
40
Regiosel.Fit%
Regiosel.Meas%
FirstGenSel.Fit
FirstGenSel.Meas
Epoxide Conversion
60
80
100
500
1000 1500
Regiosel%.Meas
Regiosel%.Simu
2000 2500
0
500
Initial Water Level (ppm)
Initial Water Level (ppm)
1000
k_init.Meas
k_init.Simu
1500 2000 2500
Fig. 15 Examples of experimental data versus model output for a 130 reactions system modeled
with only 8 dominant mechanisms. Adapted with permission from [20]. Copyright (2019) American Chemical Society
102
M. Jaraíz
values that need to be calculated and, therefore, in a considerable reduction of time
and effort (by a factor of 10 in this case).
It is interesting to note that, for example, under the conditions of some of their
experiments, a fast process, not included in the current mechanisms of Fig. 14,
shows up after about 1,000 s (Fig. 16, solid lines, simulation; dash-dot, experiment).
This may correspond to the time needed to build up a steady state concentration of an
intermediate, like FABÁH2O, that feeds a water-mediated catalytic cycle with rates
and regioselectivities different from those of the Lewis acid catalytic cycle, as
pointed out by Yu et al. In such cases, one can develop and calibrate a starting
model to reproduce the initial stages of the reaction and then add other mechanisms.
In fact, for the training experiments 1, 2, and 11 of this example, we used only the
data points up to 1,000 s. Afterward, the water-mediated and alcohol-mediated
catalytic cycles could be added, as a refinement of the mechanisms already
implemented and calibrated to a first approximation.
90.0
85.0
80.0
75.0
70.0
65.0
60.0
Regioselectivity (%)
55.0
50.0
0
2 0
Regiosel.Fit%
Regiosel.Meas%
FirstGenSel.Fit
FirstGenSel.Meas
40
Epoxide Conversion
60
80
100
50.0
60.0
First-generation selectivity (%)
70.0
80.0
90.0
Experiment 1, fitted
Experim. 20, predicted, +P2
Runs 1 to 21
Runs 1 to 17
100.0
110.0
1.0E–03
1.0E–04
k(1/s)
1.0E–05
80
110.0
100.0
90.0
80.0
70.0
60.0
50.0
79
78
77
76
75
74
73
Regioselectivity (%)
Regioselectivity (%)
First-generation selectivity (%)
72
71
70
0
0
50.0
55.0
60.0
65.0
70.0
75.0
80.0
85.0
90.0
20
40
Regiosel.Fit%
Regiosel.Meas%
FirstGenSel.Fit
FirstGenSel.Meas
Epoxide Conversion
60
80
100
500
1000 1500
Regiosel%.Meas
Regiosel%.Simu
2000 2500
0
500
Initial Water Level (ppm)
Initial Water Level (ppm)
1000
k_init.Meas
k_init.Simu
1500 2000 2500
Fig. 15 Examples of experimental data versus model output for a 130 reactions system modeled
with only 8 dominant mechanisms. Adapted with permission from [20]. Copyright (2019) American Chemical Society
102
M. Jaraíz