Synfacts 2007(6): 0604-0604  
DOI: 10.1055/s-2007-968560
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Stereoselective Synthesis of Tri- and Tetrasubstituted Alkenes from Alkynes

Contributor(s): Mark Lautens, Frédéric Ménard
K. Murakami, H. Ohmiya, H. Yorimitsu*, K. Oshima*
Kyoto University, Japan
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Publikationsverlauf

Publikationsdatum:
22. Mai 2007 (online)

Significance

This report presents a new catalytic system to achieve the carbometallation of unfunctionalized alkynes 1. Chromium salts promoted the arylmagnesiation of alkynes in the presence of pivalic acid to obtain the corresponding alkenes 3 with very high stereoselectivity. After the aryl addition, the carbometallated species can be trapped with various electrophiles to lead to tetrasubstituted alkenes 4-8.