Catalysis is a fact our daily lives. A wide variety of important commercial chemical substances are currently produced on both the fine and bulk scales in the presence of molecular catalysts that have been optimized based on specific factors such as efficiency, toxicity, cost, or a combination thereof. Recent advancements in cheminformatics-based machine learning (ML) offer chemists a way to bypass traditional Edisonian empiricism and develop more efficient approaches to optimizing catalysts. Several groups have reported successful demonstrations of ML-driven optimizations of homogeneous catalysts such as phosphoric acids and Lewis-basic ligands for metalbased catalysts involving phosphines, N-heterocyclic carbenes, and nitrogen-based ligands. Recent progress in frustrated Lewis pairs (FLPs) has expanded the practical and sustainable application of main-group catalysis, e.g., enabling the hydrogenation of unsaturated molecules without toxic/precious metals. In this context, the main-group-catalyzed reductive alkylation of amines with carbonyl compounds and H2 via the generation of FLP species has been widely accepted as a waste-minimizing process that generates valuable N-alkylated amines, whereby H2O is the only by-product. Our group and that of Soós have independently shown that triarylboranes effectively catalyze the reductive alkylation of a variety of amines with aldehydes in the presence of H2. Moreover, we have demonstrated that an FLP that consists of Soós' borane, i.e., B(2,6-Cl2-C6H3)(2,3,5,6-F4-C6H)2 (B 1a ), and tetrahydrofuran (THF) exhibits good functional-group tolerance for aniline derivatives including halogens, hydroxyl, and amide groups (Figure ). However, the direct reductive alkylation of amino acids with H2 has remained challenging, and such reactions have proceeded in only low-tomoderate yields even under forcing conditions. In terms of toxicity, the solvent THF, which also acts here as a Lewis base to generate FLPs with boranes, should be replaced with a less hazardous chemical. Given the central role of the reductive alkylation of amines using carbonyl compounds in the synthesis of e.g. pharmaceuticals, bio-active molecules, and agrochemicals, the development of a straightforward and greener protocol for derivatizing amino acids and peptides would be worthwhile.