Aggregation‐Induced Asymmetric Synthesis of 2,3‐Dihydrobenzofurans by [4 + 1] Annulation with Substituted Salicyl <i>N</i>‐Phosphonyl Imines

The aggregation‐induced asymmetric synthesis (AIAS) of trans ‐2,3‐dihydrobenzofuran compounds is achieved via the reaction of salicyl N ‐phosphonyl imines with sulfur ylide. This transformation proceeds through a [4 + 1] annulation pathway, affording products in good to excellent yields with tunable diastereoselectivities. By employing various THF/EtOH cosolvent systems in conjunction with GAP chemistry, the conventional aggregation cosolvent systems are shown to play a crucial role in enhancing diastereoselectivity and modulating aggregate formation. This is supported by studies involving aggregation‐induced emission, aggregation‐induced polarization, and dynamic light scattering. The developed protocol provides a practical and versatile synthetic approach to 2,3‐dihydrobenzofuran scaffolds, highlighting the utility of AIAS as a powerful strategy for achieving stereocontrol.