Chemists from Fuzhou University have reported a copper-catalyzed strategy for making chiral α-perfluoroalkyl organoboron compounds that contain adjacent boron- and carbon-centered stereogenic elements. The method, published in Chiral Chemistry , offers a new way to access structurally distinctive fluorinated molecular building blocks with high stereocontrol.
Fluorinated groups are widely used in molecular design because they can substantially alter a compound's physical and chemical behavior. At the same time, organoboron compounds are versatile intermediates in synthesis. Bringing these two features together in a single, precisely defined chiral structure has remained challenging—particularly when stereochemistry at both boron and carbon must be controlled.
In the new study, researchers used a copper-catalyzed asymmetric B–H insertion reaction to couple 2-arylpyridine-boranes with α-aryl-α-perfluoroalkyl diazomethanes.
The team prepared more than 40 previously unreported chiral α-perfluoroalkyl organoboron compounds. Across the study, the reaction delivered yields of up to 85% and enantiomeric excesses of up to 99%. For longer-chain perfluoroalkyl substrates, the products reached diastereomeric ratios above 20:1.
This work addresses a demanding stereochemical synthesis problem by bringing organoboron chemistry and organofluorine chemistry together in one catalytic transformation. The resulting compounds may broaden the set of chiral fluorinated building blocks available for downstream molecular construction.
The method accommodated several perfluoroalkyl groups, including CF₃, C₂F₅, C₃F₇ and C₄F₉, and tolerated a range of substituents on both reaction partners. The researchers also demonstrated a 2 mmol scale-up reaction and transformed selected products through cross-coupling, amination, phosphorylation and further B–H insertion chemistry while retaining stereochemical information.
Mechanistic experiments, including deuterium-labeling and kinetic-isotope-effect studies, helped clarify the hydrogen-transfer process underlying the catalytic reaction.
The study is a fundamental advance in synthetic chemistry. It does not test medicines, agricultural products, biological activity or clinical outcomes. Instead, it provides a synthetic platform that could support future research involving chiral fluorinated molecules.
The research was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, and institutional research funds.
