A notable feature of this total synthesis route is the modular introduction of any desired biaryl linkage via C-H biarylation of alanine derivative 17 facilitated by a Pd(II) catalyst. Therefore, improvements and the substrate scope of this C-H biarylation were investigated (Figure ). Initially, C-H biarylation of alanine derivative 17 with iodinated compound 16 was attempted under various conditions. Based on previously reported conditions, Pd(OAc)2 (20 mol%) and AgBF4 (1.5 eq.) were employed, and different solvents were screened (Table ). 11 Non-polar solvents like DCE and PhMe resulted in poor solubility of alanine derivative 17 and iodinated compound 16, leading to minimal reaction progress (entries 1, 2). Using tetrachloroethane yielded the desired compound 19 at 29%, but this was unsatisfactory (entry 3). Low yields also resulted from using HFIP and t-AmOH/HFIP (1/1) (entries 4, 5). Further solvent screening revealed that using t-AmOH/DCE (1/1) improved the isolated yield, giving 56% of the desired compound 19 (entry 6). Conversely, t-AmOH/toluene (1/1) was less effective (entry 7). Ultimately, using alcohol-based solvents like t-BuOH or t-AmOH alone significantly improved the isolated yield to 66% and 74%, respectively, indicating optimal solvents for this C-H biarylation (entries 8, 9).