Development of the Suzuki-Miyaura Cross-Coupling Reaction: Use of Air-Stable Potassium Alkynyltrifluoroborates in Aryl Alkynylations
Gary A. Molander*, Bryson W. Katona and Fouzia Machrouhi
*Roy and Diana Vagelos Laboratories, Department of Chemistry, University of
Pennsylvania, Philadelphia, Pennsylvania 19104-6323, Email:
gmolandrsas.upenn.edu
G. A. Molander, B. W. Katona, F. Machrouhi, J. Org. Chem., 2002, 67, 8416-8423.
DOI: 10.1021/jo0262356
Abstract
The palladium-catalyzed cross-coupling reaction of potassium alkynyltrifluoroborates with aryl halides or triflates proceeds readily with moderate to excellent yields. The potassium alkynyltrifluoroborates are air- and moisture-stable crystalline solids that can be stored indefinitely, which will provide an advantage in applications to combinatorial chemistry.
see article for more reactions
see article for more examples
Details
The document discusses the development of the Suzuki-Miyaura cross-coupling reaction using air-stable potassium alkynyltrifluoroborates for aryl alkynylations. This reaction, catalyzed by palladium, offers moderate to excellent yields and tolerates various functional groups. Potassium alkynyltrifluoroborates are stable crystalline solids that can be stored indefinitely, making them advantageous for combinatorial chemistry. The reaction uses 9 mol % of PdCl2(dppf)·CH2Cl2 as a catalyst in THF or THF-H2O with Cs2CO3 as the base. The method improves upon the Sonogashira coupling by avoiding toxic reagents and providing better stability and storage. The document details the synthesis of these borates and their successful application in cross-coupling reactions with aryl halides and triflates, highlighting the optimal conditions and catalyst loadings. The study demonstrates the broad applicability and efficiency of this method, making potassium alkynyltrifluoroborates a promising alternative for organic synthesis. The research was supported by various pharmaceutical companies and provides a comprehensive experimental section for reproducibility.
Key Words
Potassium Alkynyltrifluoroborates, Suzuki Coupling, Alkynylation
ID: J42-Y2002-220