To further prove that M19 is an excellent catalyst and the importance of the azetidine ring, we tested the diamine shown in Figure . This diamine was completely unable to function as a catalyst when using reaction conditions similar to those used for catalyst M19. The only observed reaction was a small amount of transesterification of methyl acrylate. This experiment further proved the importance of the structure of the catalyst being key to its functionality for the MBH reaction. The 1 H-NMR spectra recorded for this experiment can be found in Figures and.