The First General Palladium Catalyst for the Suzuki-Miyaura and Carbonyl Enolate Coupling of Aryl Arenesulfonates
Hanh Nho Nguyen, Xiaohua Huang and Stephen L. Buchwald*
*Department of Chemistry, Massachusetts Institute of Technology, Cambridge,
Massachusetts 02139, Email: sbuchwal
mit.edu
H. N. Nguyen, X. Huang, S. L. Buchwald, J. Am. Chem. Soc., 2003, 125, 11818-11819.
DOI: 10.1021/ja036947t
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Abstract
A general method for the Suzuki-Miyaura and carbonyl enolate coupling of unactivated arenesulfonates was developed utilizing Pd(OAc)2 and XPhos as ligand. The catalyst system effects the coupling of various aryl, heteroaryl, and extremely hindered arylboronic acids and carbonyl enolates with different aryl tosylates, under mild conditions.
see article for more reactions
see article for more reactions
Details
The document discusses the development of the first general palladium catalyst for the Suzuki-Miyaura coupling and carbonyl enolate coupling of aryl arenesulfonates, specifically aryl tosylates. This advancement is significant as aryl tosylates are more cost-effective and easier to handle than aryl triflates but are typically less reactive. The study, conducted by Hanh Nho Nguyen, Xiaohua Huang, and Stephen L. Buchwald at MIT, demonstrates that the catalyst system using XPhos and Pd(OAc)2 in THF is effective for various substrates, achieving high yields under mild conditions. For more challenging substrates, higher catalyst loading and t-BuOH as a solvent improved solubility and reaction rates, leading to successful couplings. The catalyst also facilitated the first example of arylation of enolates derived from cyclic and acyclic ketones, β-dicarbonyl compounds, and an ester. This work expands the utility of Suzuki-Miyaura coupling to include aryl tosylates, providing a versatile and practical method for forming carbon-carbon bonds in organic synthesis. The research was supported by the National Institutes of Health and various pharmaceutical companies.
Palladium-Catalyzed α-Arylation of Esters
W. A. Moradi, S. L. Buchwald, J. Am. Chem. Soc., 2001, 123, 7996-8002.
Highly Active and Selective Catalysts for the Formation of α-Aryl Ketones
J. M. Fox, X. Huang, A. Chieffi, S. L. Buchwald, J. Am. Chem. Soc., 2000, 122, 1360-1370.
Selective Monoarylation of Acetate Esters and Aryl Methyl Ketones Using Aryl Chlorides
M. R. Biscoe, S. L. Buchwald, Org. Lett., 2009, 11, 1773-1775.
Key Words
ID: J48-Y2003-1590
