Probing the mechanism of the Ugi four-component reaction with charge-tagged reagents by ESI-MS(/MS).
The mechanism of the Ugi four-component reaction has been investigated by electrospray ionization (tandem) mass spectrometry using charge-tagged reagents (a carboxylic acid or an amine) to favour detection. Key intermediates were transferred directly via ESI(+) from the reaction solution to the gas phase and characterized by MS measurements and MS/MS collision induced dissociation. The Mumm rearrangement (final step) was also investigated by both travelling wave ion mobility mass spectrometry and DFT calculations. The data seem to consolidate the amazingly selective mechanism of this intricate four-component reaction.
Laboratory of Medicinal and Technological Chemistry, University of Brasília (IQ-UnB), Campus Universitário Darcy Ribeiro, CEP 70904970, P.O. Box 4478, Brasília-DF, Brazil. brenno.ipi@gmail.com.
Gisele A
GA
Medeiros
Wender A
WA
da Silva
Giovana A
GA
Bataglion
Davi A C
DA
Ferreira
Heibbe C B
HC
de Oliveira
Marcos N
MN
Eberlin
Brenno A D
BA
Neto
D000588:Amines / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D005740:Gases / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization
D000588:Amines; D002264:Carboxylic Acids; D005740:Gases