A convenient pinacol coupling of diaryl ketones with B<sub>2</sub>pin<sub>2</sub><i>via</i>pyridine catalysis
Junhyuk Jo, Seonyul Kim, Jun‐Ho Choi, Won‐jin Chung
Abstract
A convenient, pyridine-boryl radical-mediated pinacol coupling of diaryl ketones is developed. In contrast to the conventional pinacol coupling that requires sensitive reducing metal, the current method employs a stable diboron reagent and pyridine Lewis base catalyst for the generation of a ketyl radical. The newly developed process is operationally simple, and the desired diols are produced with excellent efficiency in up to 99% yield within 1 hour. The superior reactivity of diaryl ketone was observed over monoaryl carbonyl compounds and analyzed by DFT calculations, which suggests the necessity of both aromatic rings for the maximum stabilization of the transition states.
Topics & Concepts
PinacolPyridineYield (engineering)CatalysisReagentChemistryCoupling (piping)Base (topology)Lewis acids and basesCombinatorial chemistryOrganic chemistryMaterials scienceMathematicsMetallurgyMathematical analysisOrganoboron and organosilicon chemistryCatalytic Cross-Coupling ReactionsCatalytic C–H Functionalization Methods