The synthetic utility of this three-component coupling is especially evident in the compound library preparation. Evaluating the potential of synthetic method to access diverse chemical space 27 is crucial for SAR exploration in medicinal chemistry. Therefore, parallel library synthesis using high-throughput experimentation (HTE) represents an efficient approach. To assess the HTE compatibility of this method, a 96-well alkyl amine 3D library expansion screening was designed. Judicious selection of 4 aldehydes (X1-X4), 4 amines (N1-N4) and 6 organoboron (B1-B6) building blocks led to 96 enumerated complex amine structures (see Supplementary Information Section 'Alkylamine library syntheses' for details). These building blocks encompass an array of diverse electronically and sterically differentiated coupling partners: 1° (B1, B2), 2° (B3, B4) and 3° (B5, B6) alkylboron reagents, (hetero)anilines (N1, N2) and alkylamines (N3, N4), heteroaryl (X1, X2), 1° (X3) and 2° alkyl (X4) aldehydes (Figure ). Many of these motifs are prominent in medicinal chemistry, such as amino acid (N4) and saturated heterocycles (N3, X4). The reactions were executed in a 96-well plate with a 420 nm LED array, and LC-MS analysis confirmed formation of desired products in 66 out of the 96 entries (Figure ). This success rates is comparable to that of other library chemistries. Representative products derived from 4 organoboron, 3 amines, and 3 aldehydes (95-102) were purified and characterized at milligram scale (Figure ). These results highlight the potential of this APBM strategy to efficiently expand the chemical space for highly complex alkylamines in a single step. Limitations were observed with the thiazole containing aldehyde (X1) and amine (N2), as little product formation was observed when they were employed as coupling partners. Overall, this APBM approach holds promise for future applications in the discovery of drug candidates in medicinal chemistry efforts and further optimization could focus on expanding the substrate scope to encompass more five-member ring heterocycles, e.g., thiazoles.