Stable BF 2 Boracycles as Versatile Reagents for Selective Ortho C–H Functionalization

The development of new boron reagents continues to play a crucial role in advancing modern organic synthesis, particularly in C-H functionalization and cross-coupling reactions. Herein, we report a metal-free, robust, and scalable multigram protocol for the synthesis of stable BF₂ boracycles that require no column chromatography, providing a practical and efficient route to access this valuable boron species. The BF₂ boracycles exhibit enhanced stability and reactivity, making them highly versatile intermediates for late-stage diversification. They undergo ipso-substitution to afford a wide array of derivatives, including halogenated (e.g., radioiodinated), hydroxylated, and azidated products. Furthermore, they display excellent reactivity in Suzuki-Miyaura cross-coupling reactions, enabling both C(sp²)─C(sp²) and C(sp²)─C(sp³) bond formation. These results underscore the utility of BF₂ boracycles as powerful tools for selective functionalization in pharmaceutical synthesis and beyond. Our work represents a significant advancement in organoboron chemistry, offering both a streamlined synthetic approach and broad applicability for complex molecule construction.