Palladium-catalyzed borylative coupling of hypervalent iodine diazo reagents with boranes for the synthesis of organoboron carboxylate.

A palladium-catalyzed coupling of hypervalent iodine diazo compounds with 2-arylpyridine borane complexes has been developed, enabling an efficient synthesis of diverse organoboron carboxylates in good to excellent yields with high chemoselectivity. Unlike traditional carbene B-H insertion reactions that form C-B bonds, this method proceeds via a borane-to-carbene hydride transfer pathway, providing a new strategy for organoboron carboxylate construction. The reaction shows broad substrate scope, good functional-group tolerance, and is scalable. Mechanistic studies support formation of a Pd-carbene intermediate followed by hydride transfer and rearrangement. Preliminary biological evaluation shows that selected products exhibit antiproliferative activity against multiple cancer cell lines, with compound 3m showing the highest potency (IC50 = 1.85 ± 0.07 µM for HCT-116 and 2.41 ± 0.01 µM for MIA-Paca-2).