Achieving high levels of chemoselectivity is a
pivotal feature of chemical synthesis. Although significant
progress has been made in this regards, lots of challenges
lie ahead. Herein, multivariate curve resolution-alternating
least square (MCR-ALS) was employed to overcome the
spectral overlapping of the reactants and products in the
model reactions of methyl-(4-formyl) benzoate by NaBH4
and acetylation of p-aminophenol by acetyl chloride. The
first-order ultraviolet/visible absorbance spectra were
recorded during the addition of different quantities of
reagent to the substrate. The absorbing species, coexisting
in the system, were detected through employing factor
analysis. The soft-modeling analysis of the evolutionary
absorbance data by MCR-ALS revealed that both model
reactions proceed through a two-step consecutive manner.
Using the obtained concentration profiles, one can obtain
an idea about the suitable molar ratio of reagent/substrate
for selective production of one of the reaction products.
Moreover, the pure spectrum of the intermediate species
could be estimated.