3.2 Reaction B
The free energy diagrams leading to P2 catalyzed by Ag2CO3 in reaction B are shown in Figure 3. In the absence of cat , R would coordinate to Ag2CO3firstly,[45] which is followed by the ligand exchange to transform into intermediate 2Bwith a barrier of 3.9 kcal/mol (TS1B ). The subsequent ring-opening would furnish P2 -coordinated complex3B , requiring the barrier of 14.9 kcal/mol (TS2B ). The infeasible ring-opening process is given in Figure S4 in Supporting Information. In contrast, from 2B , theβ -carbon elimination could also take place to lead to P1(red line in Figure 3), but the relative higher barrier ofTS2-P1B restricts this pathway. These calculated results are consistent with the experimentally observed selectivity.
FIGURE 5 Free energy diagrams leading to P1 andP2 in reaction A. The relative free energies and relative enthalpic energies (in parentheses) are given in kcal/mol