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Synfacts 2007(10): 1062-1062  
DOI: 10.1055/s-2007-969022
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Titanium-Catalyzed Asymmetric Friedel-Crafts Alkylations

Contributor(s): Mark Lautens, Praew Thansandote
H.-M. Dong, H.-H. Lu, L.-Q. Lu, C.-B. Chen, W.-J. Xiao*
Central China Normal University, Hubei, P. R. of China
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Publication History

Publication Date:
07 November 2007 (online)

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Significance

In an approach complementary to previously reported methods, the authors report an asymmetric Friedel-Crafts alkylation of indoles with ethyl glyoxylates using chiral Ti-BINOL complexes. N-Protected indoles provide higher yields and greater enantioselectivities compared to free indoles, and various substitution patterns on the benzenoid ring of the indole can be tolerated. Three other glyoxylate derivatives were shown to participate, although they lead to lower ee values or bisindole formation.