Fig. 5. Experimental and computational data related to the Michael addition catalyzed by UPypent5 and K2CO3. (a) The reaction between Malref3 and UPypent5, showing how the fraction of each type of diUPy catalyst changes with conversion. (b) The conversion of the K2CO3 catalyzed Michael addition between equimolar mixtures of Malref3 and UPypent5 (symbols) and the best fits of the kinetic model based on mass action kinetics of diUPypent, UPypent·UPyproduct, and diUPyproduct K2CO3 complexation and subsequent inter- and intramolecular catalysis (lines). The concentration of K2CO3 is kept constant (c = 36 mM), while the concentrations of Malref3 and UPypent5 are changed simultaneously (c = 1, 2, 4 and 8 mM). The reactions were performed in duplicate in CDCl3 at room temperature, all components were combined simultaneously. The results show that diluting both substrates by a factor eight does not notably reduce the reaction rate. (c) Schematic of the kinetic mass action model for the Michael addition between Malref3 and UPypent5 including diUPy·K2CO3 complexation, and inter- and intramolecular catalysis, see ESI† for details on the computational model, fits of the experimental results, and obtained reaction constants.
