MS.

LC-MS data were collected on an Agilent 1260 HPLC coupled to an Agilent 6130 single quadrupole mass spectrometer (Agilent Technologies) and an inline Agilent UV absorbance detector (210 nm) using a 3.0-kV electrospray ionization (ESI) capillary voltage. Samples were directly infused into the mass spectrometer by ESI.

Processing of MS data were conducted using a suite of macros (Igor Pro-8.0). The macros, upon user input of reactants, search the spectrum for m/z values corresponding to condensation−dehydration reactions and automatically label peaks with this information. This processing package, along with a how-to-guide, is freely available at https://github.com/GATech-HudLab/Mass-Spec-Processor. LC-MS data are compiled in SI Appendix.