Fig. 1. Functional group screening to determine strategy used to bifunctionalize propargyl carbamates. (a) Decaging reaction of substituted propargyl carbamate protected 7-amino-4-methylcoumarin 1–7 through reaction with palladium complexes. (b) Increase in fluorescence of decaging reactions over time. Propargyl carbamate protected fluorophore has quenched fluorescence which is restored upon decaging. The reactions were performed at 100 μM final concentration of the fluorophores, with 5 equiv. of allylpalladium(ii) chloride dimer 9. (c) Fluorescence screening performed with 10 equiv. Pd(COD)Cl210. The data were normalized with respect to 100 μM of free fluorophore (7-amino-4-methyl coumarin 8) plus the final concentration of the palladium complex (0.5 mM for 9 and 1 mM for 10). (d) 1H NMR data supporting hypothesis of binding of Pd(COD)Cl2 with methyl propargyl thioether motif.
