Copper‐Catalyzed Convergent Assembly of Oxaboroles via Multicomponent Coupling for Functional Molecule Discovery

Oxaboroles are privileged motifs in medicinal and agrochemical chemistry; however, stereodefined access to fully substituted variants remains limited. Herein, we report a Cu‐catalyzed multicomponent strategy that enables the rapid and convergent assembly of multisubstituted oxaboroles from readily available alkynes, organoboranes, and aldehydes. This transformation proceeds via in situ generation of alkynyltrialkylborates followed by a highly regio‐ and stereoselective 1,2‐migration. The resulting oxaboroles serve as versatile and isolable intermediates that can be transformed into a range of structurally diverse products, including tetrasubstituted alkenes, ketones, and alcohol derivatives. Notably, this platform enabled the identification of a potent antifungal oxaborole derivative (>99% inhibition against Rhizoctonia solani at 10 ppm). This work provides a general and practical platform for oxaborole synthesis that integrates organometallic reactivity with functional molecule discovery.