-fused product, whereas the bulky WingPhos ligand reverses the diastereoselectivity by stabilizing an alternative vinylogous addition transition state through steric confinement and favorable noncovalent interactions within a well-defined chiral pocket. In contrast, the BINOL-derived phosphoramidite ligand alters the relative energetics of competing N-allylation pathways, favoring a distinct regioselective N-allylation that leads to azetidine formation. The ligand-dependent steric effects, dispersion interactions, and electronic factors collectively differentiate the competing pathways, thereby clarifying how distinct chiral ligand environments modulate pathway selection in this Pd-catalyzed cascade reaction.
Zhao et al. (Mon,) studied this question.