Microdroplet Chemistry Accelerates aza -Friedel–Crafts Reactions for Three-Component Synthesis of α-Branched Amines

α-Branched amines represent a significant class of natural and pharmaceutical molecules with notable biological relevance and medicinal utility. Their efficient construction is commonly achieved through aza-Friedel-Crafts reactions. Traditionally, these transformations require high-boiling solvents, concentrated acids or metal catalysts, high temperatures, and prolonged reaction times. In this work, we present a rapid and efficient microdroplet-based approach for synthesizing α-branched amines via aza-Friedel-Crafts reactions under ambient conditions, enabled by substantial reaction acceleration of microdroplet chemistry (exemplified by a 1.54 × 10²-fold rate increase in the model reaction). Leveraging the synergistic effect between the interfacial superacids and extraneously 3 mol % I₂, 15 α-branched amine derivatives were prepared in good to excellent yields (70-93%) with a scalable production rate of 1.69 g h⁻¹. Owing to its low catalyst loading, mild conditions, high efficiency, broad substrate scope, and gram-scale applicability, this microdroplet approach offers a compelling alternative to conventional aza-Friedel-Crafts methodologies.