The benzoate ester was hydrolyzed using K2CO3/MeOH to form 9 (Scheme 5). We were pleased to see that when 9 was heated with Pd(OAc)2 (15 mol%) and 1 equivalent of Cu(OAc)2 under 1 atm of O2 in CH3CN, cyclized product 10 formed in a 32% yield (Scheme 5, Entry 1). A crystal structure of 10 allowed us to assign product identity and stereochemistry unambiguously (CCDC 2204976). The reaction yield was similar with 15 mol% of Pd2(dba)3 (Scheme 5, Entry 2), but we observed a much better result upon switching to PdCl2(nbd) and Pd(PhCN)2Cl2 (Scheme 5, Entries 3-4). Switching solvents from CH3CN to dioxane or to DMA (Scheme 5, Entries 5-6) was deleterious, but reaction performance was reasonable in DMSO (Scheme 5, Entry 7). The Yu laboratory has shown that mono-protected amino acid (MPAA) ligands are excellent in promoting Pd(II) -Pd(0) catalytic cycles in C-H functionalization reactions. Aza-Wacker cyclization reactions also proceed via a Pd(II) -Pd(0) redox manifold, and we thus hypothesized that an MPAA ligand may boost reaction performance. In line with this idea, we were pleased to see a 15% boost in yield when 1 equivalent of Fmoc-Gly-OH and 4 Å molecular sieves were added to the reaction mixture (Scheme 5, Entry 9).