Borate‐Enabled, Scalable Copper Catalysis for Suzuki–Miyaura Cross‐Coupling of Pyridylborons With Unactivated Alkyl Bromides

Abstract

ABSTRACT Alkylpyridines are ubiquitous structural motifs in pharmaceuticals, natural products, and materials science, with pyridylboron reagents ranking among the most frequently employed organoborons—underscoring the high demand for efficient cross‐coupling methodologies to access these valuable scaffolds. However, C(sp 2 )–C(sp 3 ) Suzuki–Miyaura couplings involving pyridylborons are far less developed, primarily due to catalyst inhibition by N ‐heterocycles and the inherent instability of the boron reagents. Herein, we report a borate‐enabled copper‐catalyzed Suzuki–Miyaura coupling of pyridylborons with alkyl bromides that effectively addresses these challenges. The protocol features broad substrate scope across diverse pyridylborons and alkyl halides, excellent functional group tolerance, compatibility with complex molecule functionalization, and scalability up to 100‐mmol, retaining good efficiency—thus providing a practical platform for alkylpyridine synthesis. Mechanistic studies reveal that the borate additive interacts with the base to form a bulky borate anion, which likely prevents the catalyst from inhibition.