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General, Robust, and Stereocomplementary Preparation of β-Ketoester Enol Tosylates as Cross-Coupling Partners Utilizing TsCl-N-Methylimidazole Agents

Hidefumi Nakatsuji, Kanako Ueno, Tomonori Misaki and Yoo Tanabe*

*Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan, Email: tanabekwansei.ac.jp

H. Nakatsuji, K. Ueno, T. Misaki, Y. Tanabe, Org. Lett., 2008, 10, 2131-2134.

DOI: 10.1021/ol800480d (free Supporting Information)


Abstract

TsCl coupled with NMI forms a highly reactive N-sulfonylammonium intermediate. β-Ketoesters undergo (E)-selective tosylation using TsCl-NMI-Et3N and (Z)-selective tosylation using TsCl-NMI-LiOH in good yield. Stereoretentive Negishi and Sonogashira couplings using enol tosylates proceed successfully to give trisubstituted α,β-unsaturated esters.

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General, Robust, and Stereocomplementary Preparation of α,β-Disubstituted α,β-Unsaturated Esters

H. Nakatsuji, H. Nishikado, K. Ueno, Y. Tanabe, Org. Lett., 2009, 11, 4258-4261.


Key Words

Sulfonates, Negishi Coupling, Sonogashira Coupling, Enynes, Styrenes


ID: J54-Y2008-1400